The Ultimate Freshwater Aquarium Guide

freshwater aquarium

If you are looking for pets that will entertain, relax and inspire you, why not consider owning a freshwater aquarium?

The concept of aquariums has been around for thousands of years, providing enjoyment and health benefits to both their owners and visitors. You may think that starting a freshwater aquarium is expensive.

You may be unsure as to which types of fish food are best for certain types of fish. You may not even know what types of fish are available!

Here comes the fact: Freshwater aquarium ownership is one of the pet ownership that has the lowest cost and maintenance IF you know how to do it.

A General Introduction to Freshwater Aquariums

Freshwater aquariums are very popular due to their low cost and easy maintenance.

What does a typical freshwater aquarium include?

  • A filtration system
  • An artificial lighting system
  • Air pumps
  • A heater
  • Often times power heads to increase water circulation.

What are the physical aspects of a freshwater aquarium that are an integral part of its design?

There are physical factors of the aquarium that affect the behavior and survivability of tank inhabitants. The aquatic ecosystem is very delicate. The following factors are very important because they might drastically affect the health and behavior of the aquarium ecology:

  • Size
  • Lighting conditions
  • Density of floating and rooted plants
  • Placement of bogwood
  • Creation of caves or overhangs
  • The type of substrate
  • Other factors like aquarium’s positioning within a room

The above factors compound together and affect the behavior and survivability of tank inhabitants. Water quality parameters such as

  • Nutrients
  • Waste
  • Nitrogen
  • pH
  • Beneficial bacteria population
  • Water hardness
  • Dissolved organic content
  • Temperature
  • Internal water pressure

also play a key role.

How does filtration help in a freshwater aquarium?

The filtration system is a very important part of aquarium and is vital for the maintenance of the aquarium.

A typical aquarium filtration system includes:

  • Intake Tank
  • Outflow Tank
  • Mechanical filtration
  • Activated Carbon filtration
  • Biological filtration

These filters are responsible for the removal of

  • Removal of potentially harmful nitrogenous waste
  • Removal of phosphates
  • Removal of protein build-up
  • Removal of particulate matter
  • Removal of other waste from the water
  • Maintaining the salinity of the water especially in freshwater aquariums

Freshwater Aquarium Ecology

The aquarium inhabitants excrete nitrogen waste that can become toxic for them if not removed from time to time.

How is the nitrogen produced?

  • The bacteria, fungi, and some invertebrates excrete waste in form of ammonia that converts to ammonium in water.
  • It then passes on into the nitrogen cycle.
  • It is also produced because decomposition of plant and animal matter.

Important factors to remember

  1. There are some species that metabolize the nitrogenous waste such as nitrifiers bacteria (nitrosomonas).
  2. They take in ammonia and metabolize it into nitrite which is then converted into nitrate by the nitrospira bacteria.

Strains on the freshwater ecosystem

The nitrogen cycle puts a strain on the ecosystem

It is difficult to monitor and maintain essential bacteria population.

Use active carbon and biological filters to reduce the nitrogen waste in the freshwater aquarium.

Other nutrient cycles also affect the complex ecology of the freshwater aquarium

  • The dissolved oxygen enters the system at the water-air interphase due to the air pump. At the same time carbon dioxide escapes the system.
  • Biological loading that is often required to keep phosphate cycle, sulfur, iron and other micronutrient cycles in close equilibrium also places a burden placed on the aquarium ecosystem by the inhabitants. If the biological loading is high the ecology gets complicated and can be easily disturbed. This is further accelerated by the size of the aquarium. This is so because the surface area of water exposed to the air would affect the amount of oxygen intake, physical space will limit the capacity of nitrifying bacteria moreover only a few species of plants and aquatic animals find suitable home in small aquariums.

Freshwater Aquarium Vs. Saltwater Aquarium

There are a few things that keep saltwater aquaria from reaching the popularity of freshwater aquaria are that it requires bigger tank, the fish are weaker, more amount of work is required and the prie of maintenance be it of fish or equipment, is very high.

It’s always essential to building an aquarium that mimics the conditions of the environment where the fish and other inhabitants.

Fish keeping is generally divided into aquarium habitats:

  • Freshwater (tropical)
  • Saltwater (marine)

Below is a comparison of Freshwater Aquariums and Saltwater Aquariums:

Freshwater AquariumSaltwater Aquarium
Fish LivestockFilled with guppies, mollies and tetras.Saltwater fish are brightly colored and have fascinating habits
Manage algae with scavengers, like snails and cory catsGoby guards its territory around the clock
Fish reproduce easily if the water quality, temperature and surface space existsClownfish have symbiotic relationships with certain species of anemones
Aquascaping with live freshwater plants is effectivePufferfish often swimming to the front of the tank for attention
Must make the choice of building a fish-only tank or a reef system
Light and additional water quality maintenance requirements
Aquarium WaterThe fish have their origins in streams, ponds, rivers and lakesSalt available to mix with home tap water to make a ratio comparable to seawater
The water must be de-chlorinated by adding a de-chlorinating agent to tap waterSome additives like calcium and iodine required
A pump is needed to increase the amount of oxygenMonitors for temperature, ammonia levels and pH are needed
Monitoring ammonia levels is part of the freshwater aquarium maintenance
You need to know if the fish swim in colder water or prefer shallow water depths
Aquarium EquipmentA tank, preferably with a hood, substrate for the bottomShould be at least 30 gallons for best results
A filter to process the water five to ten times per hourSmall fluctuations in water quality are amplified in smaller tanks
Your level of interest can dictate the size of your freshwater tankA protein skimmer to remove organic wastes is needed
Light is needed for plants or to see the fish at nightSpecial lighting is needed
An air pump to add oxygen is neededA live rock substrate is needed
A heater/thermometer to monitor is needed
CostsThe fish are reasonably pricedThey require a lot of time and money investment
Can be expensiveMore expensive aquarium equipment is needed
Does not cost a lot of moneyLivestock is considerably higher in cost than freshwater
Maintaining a freshwater aquarium is not time consuming

The saltwater maintenance cost is higher because it is very difficult to maintain its delicate ecosystem. However, for an enthusiastic hobbyist here are a few suggestions on how to convert a freshwater aquarium into saltwater aquarium.

  • Replace the gravel with calcareous material like crushed coral, dolomite and argonite. It buffer’s water and produces a stable environment.
  • Make sure that your equipment does not have any metallic component because the saltwater would rust it.
  • Though filtration sytem used in freshwater aquarium can be used as it is, in saltwater aquarium still you can consider getting it upgraded so that some more circulation is added so that the surface is disrupted.
  • Lighting used for freshwater system works well for a “fish only” saltwater system. Therefore, you’ll need an upgrade if you consider keeping invertebrates as well.
  • One thing that needs to be replaced is the fish food. You have to use a combination of fresh, frozen and live food in case of marine fish. The flake food should not be major portion of fish’s food.
  • When you are ready for the final replaement, change water and add fresh water that is free of nitrates so that algae problem is reduced.

Both freshwater and saltwater aquaria have their own pros and cons while the former is easy to maintain and less expensive, the latter holds the excitement of fish and aquatic life in vibrant colors and captivating forms.

Why would you choose to have an aquarium?

Aquarium keeping is a one of the most popular hobby around the world. In fact in US it is the second most popular hobby. But it isn’t without reason.

Benefits of keeping an aquarium

  • Vaastu and Fengshui advocate having an aquarium in home and office interiors. For one, it brings in water, one of the five elements of earth and creates tranquility and harmony by generating positive energy. Next it has a cooling and soothing effect.
  • Incorporating an aquarium in the home structure and design seems natural in this case since aquarium brings along peace, harmony and relaxation into your home. It works great in de-stressing lives of both young and the old. The gentle, graceful movement of fish rinses the tension and stress. You may consider watching your aquarium than TV.
  • The doctors have long branded aquariums therapeutic. They suggest that the aquariums should be placed in the busiest room of the house where all can enjoy them. The excitement of designing your own aquarium flares imagination and helps getting over depression. The colors and buoyancy of life in an aquarium adds spice and zest to life.
  • These days even kids are not too far from stress and overburdened lives. Placing a nice colorful aquarium in their room gives them health and academic benefits. The calming effect of aquarium fish helps enhancing grades. This statement is supported by scientific studies that revealed that students who own fish score higher on both math and verbal SATs, with a combined score of 200 points over their counterparts who do not have pets. High school students who keep fish have an average GPA of 3.5, versus non-pet owners at 3.2.
  • Researches also show that aquariums help people achieve healthy mind, body and soul because they help fill the leisure deficit. You can dive into the world of fish and aquarium to find rest, relaxation, tranquility and harmony that will reduce your stress and increase your health.
  • Many people profess eating fish to keep healthy. Well, aquariums are even better. You can watch the fish swim in the tank and forget about your worries. Aquariums are a very good way to relieve stress and hypertension. Fish makes people happier and healthier.
  • Keeping an aquarium in an office or cubicles helps do more creative work and produce an environment that relieves from everyday pressures. Aquariums provide many benefits. For example- having an aquarium in office provides relaxation, education and all-round business benefits. Having an aquarium in your reception area or lobby makes the clients feel “at ease” and impressed with business maneuver. However, if you place an aquarium in your personal office it instantly provides a great backdrop for conducting business, relieving work pressure and adding on to the corporate image. Aquariums are known to enhance worker’s morale, and efficiency in the work place.
  • An aquarium adds to the aesthetic appeal of a hotel or Doctor’s Clinic lobby. The gentile movement of fish attracts the attention of visitors instantly. In children’s hospitals they captivate the children’s fantasy and help them heal faster. The waiting rooms and the lobbies become more inviting, welcoming and attractive.
  • A good aquarium works great for lowering blood pressure. Since, it has life alive in it so it will definitely gain more attention than any plasma TV or expensive art in your living room. After all, an aquarium is a natural living art that brings alive a piece of the coral reef or any other live aquatic environment in your home.
  • Aquariums placed in classrooms not only help in reducing anxiety but also act as learning aids. Caring for fish teaches children responsibility, educates them about proper pet care and improves schoolwork in areas including math, science and creative writing.
  • Aquariums automatically add dynamism and vibrancy to room aesthetics. They make the room look alive and help with relaxation and stress management. So whether it is an office, waiting area, pub or any other environment, you will find this addition to your surroundings very stimulating and beneficial. It can be that corner of your home which you consider a space that is your own peaceful corner of the world.

Why is having an aquarium at a doctor’s clinic or in a hospital a very good idea?

  • It helps create a peaceful atmosphere so that the patients are less anxious and stay occupied while waiting for their appointment.
  • Ailing patients are better able to relax, focus and finish meals. They feel calmer and perform their routine tasks in a better way after viewing aquarium.
  • Aquariums help the patients heal faster since they relive stress, especially in a traumatic or postoperative case.
  • Expecting mothers feel more relaxed and relieved from hormonal depression. Their blood pressure also remains under control.

The following are reasons why cardiologists recommend that heart patients spend time looking at fish in an aquarium:

  • It has health benefits that help lower blood pressure
  • It helps to reduce stress
  • It helps the patient control their pulse rate

Best alternative for other pets, especially if you have limited space

If you have always wanted to have a pet but shortage of space kept you away from it then having an aquarium could be a great choice for you.

If you live in apartment, dorm or in any type of housing where having dogs and cats as pets is not feasible, aquarium can really be a blessing and a good option for a pet.

It is a great way to get over the monotony of routine life.

Due to their wondrous effects on our lives you can spot an aquarium anywhere in

  • Professional offices
  • Private residences
  • Retirement homes
  • Doctors waiting rooms
  • Restaurants Reception and lobby

Aquariums give something that cannot be purchased by money and that is tranquility. It is not only a wonderful possession that grows into an addictive hobby but also a very thoughtful gift.

Choosing the right Aquarium

There are different types of aquarium available in the market depending upon the kind of fish you keep, water conditions, shape, size, material and various other factors.

Initial cost and the long-term maintenance costs also govern the type of aquarium people choose for themselves.

Starting from a single fish plain glass container to an intricate ecosystem of reef tank, aquariums are available in whole lot variety.

The most popular type of aquarium is a fresh-water aquarium. This chapter discusses various options in freshwater aquarium and argues on why one is better than other.


You must setup your aquarium where you spend most of your time but unfortunately such places have less available space so first consider how much space you can spare for your aquarium.

  • You must choose a room where you will not only be able to view and enjoy the aquarium but also maintain it properly
  • There is a space bubble around an aquarium in a fashion similar to that in human beings. It should have enough “space bubble” around it
  • The location chosen for the aquarium should be such that it is close to electric and water supply. You should there for get the plumbing and electrical work done before purchasing the aquarium
  • Aquarium should be placed at a place where it does not receive direct sunlight. Also they should be kept away from heating and air conditioning vents and room entrances because they have the ability to adversely affect the thermo stability of the aquarium, which is a vital factor to have healthy aquarium ecology
  • You should choose a location for your aquarium that can withstand the weight of the full aquarium. Remember, water weighs 8lbs per gallon. A tank carrying 20 gallons of water can weigh 160lbs without adding the weight of gravel, inhabitants and other aquarium accessories


Once you have decided on the location of your aquarium, you’ll have a better idea what the space constraints.

  • As an experienced aquarium owner, the suggestion is to get the largest tank keeping in mind the space and cost you can afford.
  • As a first time owner, you should start with a smaller tank. It gives you a fair idea of how you should maintain your aquarium and make things work without a huge cash outflow. You can get tanks in 10, 20, 25, 29, 55, 75 and 90 gallons. Once you have understood the water chemistry and fish care, you can get a larger tank.
  • You must also consider the minimum space required by the inhabitants to thrive in a healthy way. If you cannot provide that minimum space you must consider selecting another fish type.

Reasons to get a larger aquarium tank

  • A larger water volume dilutes toxins better which is good for the health of the fish
  • It ensures faster aquarium cycles which are less stressful the fish.
  • It governs the maximum number of fish that can safely thrive in it. There is a thumb rule for deciding size of aquarium. It states that, thicker bodied fish require more space than a slim bodied fish. So you must select the largest possible tank as allowed by your space and budgetary constraints.
  • Larger aquarium tanks are really easy to maintain. It is easy to maintain water chemistry in a larger tank. This automatically reduces a lot of work. A regular partial water change requires just one more bucket of water than that required for a small tank. Since you already have the bucket and siphon ready and your hands are already wet, it means just a few extra minutes of time. Smaller tank need not necessarily mean easier maintenance. Larger tank would mean larger exposed surface area so more amount of dissolved oxygen in water. So in case of smaller tank you might have to invest higher on a stronger power head.
  • While buying Freshwater aquarium you not just need to consider the tank size but also the size of heater and filter as well and the amount of substrate.
  • For tanks larger than 50 gallons, have two smaller heaters rather than one large heater. This way the heat gets more evenly distributed.

Important to note

  • Make sure you calculate the correct minimum required filter. All the water in your tank should pass through the filter at least four times each hour. If the filter choices are either 100 or 150 gallons per hour, you should purchase the 150-gallon filter
  • Your aquarium should have 2 inches thick layer of substrate. The general mix of gravel and rock makes up for a pound of substrate per gallon of water. However, in case of an unusually shaped aquarium you may require less or more substrate


Aquarium shapes have come a long way. There are a lot of creative innovations in shapes of aquarium on the market.

However, when you select an aquarium tank of a particular shape you must take into consideration certain factors attached with the tank shape that can affect the health of the aquarium inhabitants.

Wide and long

  • A wider and longer tank provides more air-exposed surface area that promotes oxygen exchange. For example it is better to go for a 75 gallons tank than a 90 gallons tank with same surface area even though it carries more water than the former.


  • It allows enough surface area for oxygen exchange and enough long, open room for fish to swim.
  • Avoid tall thin aquarium tanks and prefer buying longer ones. The taller ones would require stronger aeration, meaning stronger power head elevating the initial investment and the long-term cost of maintenance. Taller tanks cannot bear as large fish load as shallower and longer tanks can do.

Other Shapes

  • For aesthetic purpose you can think about various aquariums with shapes like tall octagons, hexagons, cubes or cylinders.
  • Though, the standard is a long rectangle, which looks larger than its actual size.


You can get an aquarium made of various materials including:

  • Glass
  • Acrylic
  • Plexiglas and other materials


Pros of Plexiglas Tanks
  • It is heavy
  • Scratch resistant
  • Cheaper per gallon
Cons of Plexiglas Tanks
  • It has a higher index of refraction
  • Easier to break


Pros of Acrylic Tanks
  • Lightweight
  • Crack resistant
  • Easier to cut holes into to accommodate plumbing
  • Can provide better views because of curved front corners
  • Can come in many interesting molded shapes
  • Provide better insulation
  • Acrylic is clearer than glass.
Cons of Acrylic Tanks
  • Higher cost
  • Greater tendency to scratch
  • Chance of changing appearance over time
  • Need for increased support: Unlike the glass tank that requires support only along the edges, acrylic tank requires a special stand that provides support along the entire bottom of the tank.

Combinations Aquariums

Buying a combination aquarium package saves you a lot of time, money and effort.

A combination package includes:

  • Filters
  • Lights
  • Heaters
  • Tank

You can start off with your aquarium as soon as possible.

NOTE: You should be careful about the quality and price of each freshwater aquarium component in a combination pack.

Fish Needs

Before selecting a tank, the type and number of fish should be considered.

Some fish require more space to thrive. For example an Arowana or Oscar cannot survive in a 10-gallon tank.

However, you may buy the tank first and then decide on the type of fish you want to keep but you’ll get the best aquarium keeping experience only if you decide beforehand.


A good freshwater aquarium has a setup cost between six and ten dollars per gallon of water in the tank.

The beginners can do well with a 10 to 20 gallons aquarium so the initial setup cost is quite nominal.

Freshwater Aquarium Inhabitants, Plants and Accessories

Freshwater Chemistry, Inhabitants, Freshwater Aquarium Plants, Accessories, And More.

Freshwater Chemistry

pH, nitrate, salinity and temperature are critical parameters in freshwater chemistry within a freshwater aquarium. Ammonia and nitrite pose a major problem for nitrogen cycle.


The freshwater aquarium inhabitants are very sensitive to the pH and salinity levels.

On an average a freshwater inhabitant cannot survive salinity level above 0.5%. Invertebrates are most sensitive to pH fluctuations of 0.2 per day they are also more sensitive to the nitrates.


The temperature range that the freshwater aquaria inhabitants usually tolerate lies between 75F to 80F (24C – 27C), with 77F (25C) being a good midpoint.

Unchecked temperature variations lead to fish stress and diseases. Thus, a good heater/ chiller should be installed in a freshwater aquarium.

Alkalinity and Calcium

Alkalinity and Calcium content are some other parameters that should be born in mind. The aquarium inhabitants need a regular supply of trace elements.

Thus, you should use fish food that supplies all the necessary amounts of essential fish nutrients.

The protein skimmer of the aquarium might strip the water off these nutrients so you should frequently keeping adding a dose of them.


If the salinity level goes high in freshwater aquarium it can lead to fatal repercussions for the inhabitants.

The osmotic pressure in the body of freshwater inhabitants gets disturbed with high salinity in water.

This is the reason why freshwater aquarium maintenance involves frequent partial water replacement. The chemical filters fitted in freshwater aquarium have to take care of the water salinity level.


Choosing the right inhabitants for your aquarium requires a bit more thought than simply matching their colors to your couch.

Choosing fish is the most fun part of getting an aquarium for oneself.

The number of fish you can have in your freshwater aquarium depends on its shape and size. Try to allow an inch of fish per gallon of water.

How to correctly introduce fish into a new tank

  • Before you add any fish to the tank you must quarantine it for a while
  • Introduce the new inhabitant slowly to the tank
  • Equalize the water temperature by floating the bag containing the new inhabitant in the tank and keep adding the tank water periodically to the bag water
  • After you have added the new inhabitant to the tank ensure that it has enough hiding places for the beginning
  • Make sure that you keep lighting dimmer than usual for a few day
  • Do not add more than four fish at a time to avoid any kind of chemical imbalance in the tank
  • Do not experiment by mixing and matching the tank inhabitants

Important note on fish species

If you decide to have a community tank or a single species tank, make sure you research the species first.

  • Some fish are predatory or aggressive so they should either be kept in a species tank or with other predatory species only if you are really keen on a community tank – Aggressive species include Oscars, Jack Dempsey and many cichlids
  • Some fish are slow feeders, or are very shy. Such fish should not be added to a community tank. A good example of this is Discus fish

While selecting a freshwater aquarium inhabitant you should always take into consideration certain factors that will result in the right ecosystem in the aquarium:

Temperament: Peaceful, semi-aggressive, or aggressive

Lighting needs: Bright light or subdued light

Habitat needs: Plants, rocks, or plants and rocks in the aquarium

Swimming level: Top, middle, bottom, or all levels of the aquarium

There are a large number of fish that are ideal for freshwater aquarium. Some of the commonly kept species include:

a) The Live-bearing fish: Live bearing fish do not lay eggs. Instead, they give birth to live, fully formed young ones, which are capable of swimming and feeding as soon as they are born. They include freshwater species like guppies, platys and swordtails. The guppies are natives of South America, Barbados, and Trinidad. They can be easily bred in America, Asia, and Europe. They do well in community tanks provided there are no aggressive inhabitants around and he number of males and females are equal. Swordtails are the first to jump out of the aquarium when stressed or involved in a frantic courtship. Therefore, enough plants must be planted in the aquarium as hiding places and as deterrents to their impulse to jump. It’s also a good idea to purchase an aquarium cover that fits well.

b) The Schooling fish: Tetra, barbs and danios are the best schooling fish that can be good addition for a freshwater aquarium. These are generally small and do great in community tanks. The Neon, Glowlight, Lemon, Cardinal, and Emperor Tetras are amongst the favorites of aquarium enthusiasts. These fish require a lot of aquarium plants to thrive and do well as pets.

c) Egg laying Fish: As the name suggests these fish reproduce by laying eggs. There are many egg-laying species of freshwater fish that are popular amongst the aquarium enthusiasts. Catfish like armored catfish, Cory catfish, glass catfish, sucker mouth catfish are very popular. Then there are the plecos, common hatchet fish, cichlids, angelfish, discus, electric yellow, cyprinids, barbs and many more. Cold-water fish include Gold fish, common carp, koi, daces, danios, knife fish and eels, labyrinth fish and loaches.

Besides, the fish invertebrates are very commonly kept in freshwater aquaria. There are a number of snail, shrimps and crayfish species that are commonly found in freshwater aquaria. Some of them include freshwater inhabitants like:

  • Apple snail
  • Japanese Glass Shrimp (Caridina japonica)
  • Caridina serrata
  • Macrobrachium lar
  • Carambellus montezuema
  • Procambarus species

These invertebrates help achieving a more aesthetically appealing aquarium as well as more balanced aquarium ecology.

They require more care than the freshwater fish because they are more sensitive to the salinity levels, calcium content, pH levels and temperature.

Hence, you might have to be on your toes for maintaining the freshwater tank having invertebrates but all the effort is worth it with the kind of zest they add to the aquarium.

Freshwater Aquarium Plants

Plants are a vital part of freshwater aquarium ecology.

  • They keep the correct water balance in the aquarium
  • They have a very critical role in the nitrogen cycle because they convert the absorbed nitrates into various essential nutrients such as plant proteins that herbivorous fish consume, and dissolved oxygen that fish “breathe” from the water
  • Plants are responsible for maintaining water quality of the aquarium by helping maintain the pH level, dissolved oxygen and carbon dioxide levels and the salinity levels
  • Plants add to the overall aesthetic appeal of the aquarium. They make the tank environment look more natural and secure for the aquarium inhabitants

It’s a great idea to include two types of plants in their freshwater aquarium setup.

They are submersed (in water) and immersed (out of water/floating) types of plants. Each of the types has its own function and benefit for the aquarium inhabitants and the overall habitat as well.

Before buying aquatic plants you should

  • Take care that they do not cause chaos in your aquarium’s aquascape once they grow up
  • They should match the natural environs of the aquarium inhabitants. If you have more number of fish and invertebrates that are shy then thick foliage will do the trick. If you have herbivorous fish avoid plants that are either too small or their leaves are too small or soft
  • Be careful about the lighting, temperature and water composition aspects of aquarium
  • Not restrict yourself to the conventionally used aquatic plants only you could add plants of different colors, shapes and sizes.

Submerged Aquatic Plants

The Submersed aquatic plants have subgroups namely

  • Tubers
  • Rooted
  • Cuttings
  • The tubers are sold slightly sprouted.
  • The one that is sprouted and rooted stands a better chance of survival even though most of the tubers are quite hardy and viable
  • Like the non-aquatic plants they also hibernate for a season and shed leaves. In this season they should be placed carefully in a cooler tank and the returned to the tank to bloom again
  • They have flowers that produce seeds that can help grow new tubers. Examples include water lily, lotus and elephant ears
  • They are the most commonly found aquarium plants
  • They are planted individually in the aquarium for growth and proliferation
  • They are commonly used as tall backgrounders and clustered fore grounders. Examples include Amazon sword, giant and dwarf sag, java fern etc.
  • Cuttings are essentially un-rooted aquatic plants top
  • They have finer and smaller leaves as compared to their rooted counter parts
  • Cuttings are sold in bunches but they should be planted individually for maximum proliferation of light to the bottom leaves. They make for great hiding places for shy juvenile fish. They are prone to collecting ‘dust’ if filtration is not done properly. Examples are cabomba, rotala, bacopa, hornwort etc.

Immersed Aquatic Plants

  • Immersed plants are mainly floating plants since they thrive out of water.
  • They don’t need an anchor of substrate
  • Their roots hang freely in water
  • They help the aquarium fish to hide from the predators
  • Their roots should not touch the lighting fixtures. Examples are water lettuce, butterfly fern, ricia, java moss etc.

Aquarium Accessories

The aquarium accessories help creating a near to natural environ for the aquarium inhabitants and they add to the aquarium decor.

There is no end to the creativity that can be put in doing your aquarium decor. It’s the same way, as you would do your home interiors.

You can use anything from plastic plants, toys, aquatic animal replicas, rocks, driftwoods, backgrounders and many more things.

However while selecting these accessories you must take care of few points that are given below.

1. Address requirements of all the fish: This is a very valid point for community tanks. You must take care that habitant requirements of all the species are fulfilled. Nocturnal breeds should have enough caves and shells for them while the territorial and the schooling species should have enough natural shielding of plants for them.

2. Non-toxic Decor: You must avoid metallic, oily, water-soluble or dirty aquarium accessories.

3. Aqua-scaping: You must pre-plan the decor of your aquarium. This is called aquascaping it is the same as you do landscaping of you garden and home interiors.

Types of Aquarium Accessories

Once you have designed a layout for your freshwater aquarium it’s time to get into some creative action.


You can start off with having something of an eccentric substrate.

Depending on the type of fish you keep you can choose between loose sand or different grades of gravel in varied vibrant colors.


  • Experimenting with the colors of the substrate you must remember that though the electric blue substrate may appeal your eyes but it might look un-natural to the aquarium inhabitants.
  • Too much of dark color gravel do well for those fish that prefer low-lit habitats and a sugar white gravel might do bad for them since it would reflect a lot of light.
  • So while considering the type of substrate make sure you not just consider the aesthetic aspect but also the requirement of your pets.

Rocks are another type of aquarium accessories that work wonderfully well for creating a natural environment for the aquarium inhabitants.

  • Some rocks are very colorful and aesthetically appeal to you but contain minerals that you might not want in your aquarium. Especially, if they add to the salinity level in your freshwater aquarium
  • You should not place rocks too close to the walls because they might exert pressure on the glass and may even break it
  • If you are using a rock pile formation, glue the rocks together to avoid the danger of them toppling on the inhabitants or the aquarium walls
  • Rocks, green slates, riverbed stones, and colorful pebbles are great to work with because they look natural, and go well with plants and driftwood.

You can pick driftwoods from the beach or any water logged location and use it imaginatively in your aquarium decoration.

  • Make sure that it is not a decaying. It might carry along harmful bacteria and parasites
  • Always scrub, rinse and soak wood before adding it to the tank
  • Driftwoods work best for creating shady areas and hiding places for shy or nocturnal species

Choosing the best Aquarium Stand is vital.

Aquariums can get really heavy once they are filled with water, substrate and other aquarium accessories and equipment.

A larger, heavier aquarium should be supported by a suitable stand that is both strong and durable. The stand’s strength should match the gallon capacity of your tank.

Some stands are built to uphold rectangular tanks, while others are shaped to better accommodate aquariums with bow-shaped fronts. Be sure to choose a stand that is suited to the shape of your aquarium.

3 Factors that should help you make the right decision on which Aquarium Stand to buy are:

  1. The size of the stand
  2. The size of the stand
  3. The shape of the aquarium

How to Set-Up Freshwater Aquariums

Once you have meticulously chosen the aquarium tank, inhabitants, plants and accessories, you need to set up the aquarium.


  • Place your aquarium tank at a suitable location. The location should be such that it is close to plumbing as well as electric connection
  • If the location you choose does not suffice for the above two things you should get some plumbing and electric work done
  • Select a location that is strong and sturdy enough to bear the weight of an object that weighs over 160 lbs for 20-gallons volume – final weight of the aquarium, after it has been set is much higher
  • Make sure that the location you choose aesthetically compliment your aquarium size, shape and layout

What should you do if the location is not sturdy enough?

  • Get a wooden or metallic aquarium stand to house your freshwater aquarium
  • After placing your aquarium on the stand or where you want to place it, check the level.
  • If the tank does not seem leveled and appears unstable then shim the stand or look for another suitable location.
  • Add a 3/4-inch Styrofoam sheet under the tank to distribute the weight evenly. If this is not done stress will be put weight on the seams and could cause an eventual leak.
  • Avoid placing the aquarium in direct sunlight or near a bright sunny widow. This encourages growth of algae
  • Avoid placing the aquarium near air conditioning and heat vents. This might complicate the water temperature
This video shows you 8 you can use to decide where to put your aquarium.


Clean and rinse the inside of the aquarium tank completely.

DO NOT use soap or detergent to clean an empty aquarium. Use warm salty water to clean an empty aquarium. Soap and detergent are non-biodegradable substances they don’t easily wash off from the surface completely and always leave behind some traces even after thorough rinsing.

  • Soap traces can enter the food chain inside the freshwater aquarium and adversely affect the health of plants and other inhabitants
  • Soap traces can lead to high pH instability inside your freshwater aquarium, posing a danger for health of the inhabitants

What should I do after cleaning a new aquarium?

  • Place a foil or a background paper on the outside of the back of the aquarium
  • A good background paper makes a great backdrop to work on while setting up a creative freshwater aquarium
  • It adds colors and a feel of natural environment for the aquarium inhabitants
This video shows you how to clean new aquarium


Once you have set up the tank in the desired position it’s the turn of adding gravel.


  • Add plates if your aquarium uses under gravel system
  • If you use cable heating, then add the cables according to the manufacturer’s instructions

Types of aquarium substrate

Your aquarium substrate can be:

  • Gravel
  • Sand
  • Dirt
  • Crushed marble
  • Artificial substrate in different colors


  • Choose the right substrate for freshwater aquariums
  • Remember that sand particles clog together and stop water from flowing through the filter

Cleaning the Gravel

  • Wash the substrate thoroughly with freshwater before adding it to the aquarium
  • Make sure that the water is clear before stopping the cleaning
  • Rinse the substrate again to make sure all dirt and unwanted particles are gone
  • You may even boil the gravel to get rid of the harmful bacteria, parasites or traces of algae. You can use gravel from an already established tank so that it already has cultured colonies of nitrifying bacteria

Adding the gravel to the tank

  • If the gravel is to be “banked” or “terraced,” add the appropriate structures to do so
  • Add the washed gravel to about a depth of 1 to 3 inches, depending on whether or not you are using an under gravel filter or not
  • Place the gravel in such a way that it slopes higher in the back and lower in the front. This makes the view of your aquarium such that everything is towards the front of the aquarium.
  • Before you start adding rocks and wooden decorations fill the aquarium half way.


Rocks and wood decorations make a good background for fish. Also, they add to the natural habitat appeal of the aquarium.

  • Position rocks on a stable footing to avoid accidents
  • Heavy rocks should be placed on the tank floor on a piece of Styrofoam


  • Before adding the rocks to the aquarium soak them for a week in a bucket of water to remove the harmful acids and leach out the other potentially dangerous impurities
  • Make sure that the rocks have no lines and veins of metal in them. They are unsuitable because they affect the water chemistry and cause damage to the inhabitants’ health.

Adding rocks to the tank

  • Embed the rocks in the gravel which provides a firm base
  • Use the rocks to construct caves & recesses to make for a more interesting view and provide shelter for more timid fish.
  • DO NOT cover the entire bottom from end to end. This will limit the water flow through the gravel bed
  • DO NOT over do your creative work on the rocks and wood decorations
How NOT to Add Substrate to an Aquarium


Water temperature is one of the critical factors to ensure good health of the aquarium inhabitants.

Place the heater at such a place where maximum water circulation takes place. This will ensure that water gets uniformly heated.

Most tropical fish do best at 76 to 79 degrees.

Cold-water fish prefer a range between 50 and 70 degrees.

What size of Aquarium Heater should I buy?

There are several factors that might affect your choice of heater. They include:

5 gallon Aquarium
  • Heater size to raise the temperature by 10 degrees – 25W
  • Heater size to raise the temperature by more than 10 degrees – 50W
10 gallon Aquarium
  • Heater size to raise the temperature by 10 degrees – 50W
  • Heater size to raise the temperature by more than 10 degrees – 100W
20 gallon Aquarium
  • Heater size to raise the temperature by 10 degrees – 100W
  • Heater size to raise the temperature by more than 10 degrees – 150W
29  gallon Aquarium
  • Heater size to raise the temperature by 10 degrees –150W
  • Heater size to raise the temperature by more than 10 degrees – 200W
40 gallon Aquarium
  • Heater size to raise the temperature by 10 degrees – 200W
  • Heater size to raise the temperature by more than 10 degrees – 300W
55 gallon Aquarium
  • Heater size to raise the temperature by 10 degrees –300W
  • Heater size to raise the temperature by more than 10 degrees – 400W
75 gallon Aquarium
  • Heater size to raise the temperature by 10 degrees – 400W
  • Heater size to raise the temperature by more than 10 degrees – 600W
Where should I place the aquarium heater?
  • The heater should be placed next to the filter output or pump for maximum flow. The water in the aquarium water will help to spread the warmth from the heater to the rest of the tank
  • You will need to install a thermometer in a corner opposite from the heater to ensure that the heat is reaching the other side of the tank

Should I leave the Aquarium Heater on at all times?

Simply put, yes.

The heat is regulated by the internal thermostat in the Aquarium heater and should turn off when it reaches a specific preset temperature.

How to ensure you have the optimal temperature
  • During installation of the heater, let the equipment acclimate to the aquarium water’s temperature for 20 to 30 minutes before plugging it in
  • Once you turn the heater on, make sure that it is fully submersed in water
  • If the heater needs to be removed from the tank for repairs or maintenance, wait at least 30 minutes for it to cool down before handling.

What are the best Aquarium Heaters?

You should always get a good quality aquarium heater which is safe and reliable.

Poor brands often fail due to overheating, shutting down, or cracking.

Below is a list that we recommend:

Air Pump

Aeration provides for the dissolved oxygen, which is a vital water quality parameter.

The air pump does this job for a freshwater aquarium.

However, when air tubing is connected to an air stone or decoration, water may back-siphon into the tubing if the pump is placed at a level lower than the water level of the aquarium.

To check this you must place the air pump at a higher level or install an anti-siphon valve in the airlines.

Aquarium Air Pumps that we recommend:


Filters are the ultimate equipment required as a mandatory aquarium installation.

It is required to maintain the water quality of the freshwater aquarium.

Most of the aquarists use under gravel filter set up because of its stability and ease of maintenance.

Click here for more on Aquarium Filters

We recommend the following Aquarium Filters:

Water Quality Monitoring

Once you have installed all the aquarium set up equipment and placed all the accessories, you can begin adding water to the tank.

Adding water into the tank

  • The water should be Luke warm (20-22¡C)
  • Add water using a hose running onto a rock or into a container without disturbing the gravel
  • Continue adding water till it is about 2 inch from the top
  • You may add ordinary tap water but let it settle down for some days before you add fish or else the fish would die because of the chlorine present in it
  • You can also make use of the de-chlorinator to get rid of this chlorine
  • After the water has been filled, plug on the heater and the filter
  • Let the environment set in overnight

Why you should monitor the water?

Monitor the water quality and observe the installed equipment for at least 2 to 3 days.

  • To ensure the water is of good quality – use a good de-chlorinator because the tap water you added to your freshwater aquarium has high level of chlorine
  • Add sodium thiosulfate to tap water immediately to neutralize the chlorine
  • You must also add a dash of aquarium salt or kosher salt to the freshwater aquarium. The amount could be 1 tablespoon per 5 gallons of water. However, during maintenance remember water evaporates not salt so salt levels should be checked.
  • Check the pH of the water before fish can be added to it. Freshwater fish can generally tolerate a pH of 6.5 to 7.8 so you must set a ph range according to the requirements of the type of fish you want to keep in your aquarium
  • Also keep an account of water hardness
  • Monitor ammonia and nitrite levels until they are zero

We recommend the following Aquarium Water Monitors:


Lighting is also as important for healthy aquarium ecology as is any water quality parameter so be sure that you install a good lighting system in your aquarium.

The type of lighting is immaterial especially if no plants are grown. Light the tan only for 10 to 12 hours to minimize algal growth.

Also avoid using colored incandescent lights since they can cause ill effects. Lighting is important for plants since they require it for photosynthesis and growth. There are several types of lighting systems available in the market.

a) Fluorescent tubes – These are the most popular type of aquarium lighting system. They consume little power, produce little heat, and provide an even distribution of light. You can get them in varied types. The light output also can be increased by using a reflector or foil on the ceiling of the hood. However, their intensity decreases with time so they have to be replaced every six months.

b) Mercury vapor lamps – This lighting system is not too commonly used but they work wonderfully for tanks that are deeper than 20″ (50 cm). These lights require special fixtures.

You can also install a timer to auto-control the timing of light so that it stays on only for about 12 to 14 hours a day and after. You can also use a dimmer switch, which can be used to vary the levels of light through the day.


When you add fish to your freshwater aquarium first thing you’ll want to know is how many of them you can have.

Well, the stocking capacity of a freshwater system is determined using two formulas for the amounts of fish you can safely keep.

a) Simple method: This is straight and simple rule of keeping one inch of fish per gallon of water. Surface area (for oxygenation) is not taken into account, neither is filtration system (waste removal) nor general size of fish. In this way it can be a drawback since, a fish that is 6 inches long needs a lot more oxygen than 6 fish that are 1 inch long.

b) Surface method: The surface area of the aquarium is taken and divided by 12 to get the number of inches of fish the aquarium can house. It takes into account the shape of the aquarium but not the size of fish and the efficiency of filtration system. It favors are shorter and wider aquariums over the taller and skinnier ones.

Another point to be noted here is that cold water aquariums can hold 2 and half times less fish than a normal tropical freshwater aquarium.

So the surface area needs to be divided by a factor of 30 rather than a factor of 12.

Now that you have your fish do not add them immediately. You must acclimatize them first.

Make sure that the temperature of the water in the bag containing the fish should be very close to that in aquarium tank.

Add new fish to the tank at night, when the lights are off or when the resident fish are being fed. So, that they are preoccupied with something and are less likely to harass the new entrant.

The fish must be added only when the chemical levels in the aquarium are appropriate and the temperature is within tolerances.


After the aquarium has been set and ready for a display of your prized possession remember to place a cover over it.

No matter what type, size or shape of tank you choose, you must include the cover.

The cover will reduce evaporation and lessen the chances of fish jumping out.

You can find your Nemo a safe and lively abode by just a little effort that surely pays not in money but with joy and aesthetic appeal.

Maintenance of your Freshwater Aquarium

Now that your freshwater aquarium is up and running, you need to focus on its maintenance.

To keep a freshwater aquarium in top condition, you do the following:


It is important to maintain a nutritious diet full of vitamins and other nutrients.

Most of the freshwater aquarium fish eat anything including:

  • Flakes
  • Pellets
  • Live foods such as Daphnia or Tubifex worms

Important to remember about fish feeding

  • Do not feed large flakes or large lumps of fish food
  • The fish should like the food
  • The pieces should be small enough for the fish
  • You should feed your fish 2 to 3 times a day in small helpings. If the fish have a good appetite, they should eat the whole food in 3 to 5 min. If that does not happen, you might be over feeding the fish
  • Try and keep the fish “fasting” once or twice a week. It improves their appetite. After all, they go without food for weeks together in their natural habitat

Water Chemistry Maintenance

Freshwater aquariums need partial water changes on regular basis.

  • You must change at least 10 to 15% of tank water every week
  • Siphon out 10 to 15 % water from the tank and replace it with new, de-chlorinated water


  • Temperature of the new water should be close to that of tank water
  • You must monitor the water temperature

Ammonia and Nitrates

Ammonia and nitrite levels are very crucial parameters.

  • They vary according to the various steps in the nitrogen cycle
  • You should check the ammonia and nitrite levels every two weeks
  • Ammonia is produced as a result of waste excreted by the aquarium inhabitants. Ammonia gets converted into Nitrite during the nitrogen cycle. Nitrite level keeps rising if you do not change water and it reaches its toxic level of 0.1 ppm
  • Add chloride salt on regular basis to your fresh water aquarium – a tablespoon salt in a 300-gallon tank


You should always keep an eye on the salt concentration in a freshwater aquarium

  • Remember what that even when water evaporates salt does not
  • Make frequent water changes to reduce the concentration
Why is salinity in a freshwater aquarium important?
  • High salt concentration causes a disturbance in the osmotic pressure. The water will try to dilute the fish’s body until both sides are equal. The fish will therefore constantly eliminate the water mainly through respiration and urine
  • Higher levels of salt in freshwater aquarium tank can lead to osmoregulatory stress amongst the aquarium inhabitants
Cleaning the salt off
  • Scrub off any salt and minerals that might get deposited on the hood or edges of the aquarium using vinegar. Thoroughly rinse off (do not use soap or detergent!)
  • Regularly replace the water with fresh de-chlorinated water to keep your freshwater aquarium’s water chemistry in balance

pH and water hardness

pH and hardness are two other parameters that can cause havoc for freshwater aquarium chemistry.

Most of the freshwater species are highly sensitive to pH fluctuations and the water hardness causing ions.

The pH of the water should be close to neutral. For freshwater aquariums, it should be between 6.5 and 7.5.

Try and keep the concentration of the hard water ions like calcium and magnesium ions very low.


Algae deposit is one of the major concerns in freshwater aquarium maintenance.

  • It upsets the water chemistry
  • It disrupts the aquarium ecology
  • Can be ground for breeding disease-causing parasites

Algae generally get deposited on the tank walls, rocks and decorations, and the gravel. You therefore have to scrub the tank and the gravel.

How do I remove Algae in a freshwater aquarium?

  • If you have fish in the tank, introduce appropriate algae eating fish
  • If you do not have any such fish in your tank and the algae get deposited then scrub it with brush, algae scrubber pad, algae scrapper, razor blade (for stubborn algae), or any other algae treatment method suitable for freshwater aquarium. Be careful that you do not scrub away the tolerable algal deposits, which assist in growth of some aquarium inhabitants. You should scrape the tank walls at least once a week
  • Clean the aquarium hood and scrape away any algal deposit on it a well. Do not use soap or detergent to clean away the algae
  • Introduce aquarium inhabitant to the tank that feed on Algae – such as Japanese trap door snails, Pomacea Bridgesi, mystery snails and Malaysian Trumpet snails

How do I prevent Algae growth in a new freshwater aquarium?

  • Soak new plants in a 1:20 solution of bleach in water
  • Let the plant sit in the water for two minutes
  • Then rinse the plants with cool running water followed by dipping it in de-chlorinated water to remove any left behind bleach


Gravel is cleaned using a siphon with a funnel-like attachment or a strainer attachment

  • Submerge the hose in the tank
  • Place your finger over one end and place other end in a bucket or sink
  • Move your finger to get the decanting into the bucket or sink
  • Be careful that the fish don’t get sucked
  • When 15 to 20% of the water has been removed add fresh de-chlorinated water
  • Level the gravel after the cleaning

Biological Gravel cleaners

You can also consider the natural way of cleaning the gravel or the substrate by introducing the Malaysian Trumpet snail that consumes the algal deposit, fish detritus and left over food.

Health of the Aquarium Inhabitants

You should monitor your aquarium every day for any possible signs of:

  • Diseases
  • Stress
  • Uneasiness amongst the aquarium inhabitants
  • Plants neglect of damage


Many plants hibernate in a particular season of the year, i.e. they shed their leaves.

  • Such plants should be transferred to another tank for that particular season
  • Trim the excessive growth and replant some of the live plants
  • Remove any dead or dying leaves from plants.


It is an advantage with keeping fish as pet that if you take little care of them and maintain good habitat conditions for them, diseases are a rarity.

However, even when diseases occur there are some clear symptoms that, if observed carefully, can prevent the situation from going out of hand.

Fish disease can also be a result of protozoa. These are one-celled parasites that grow rapidly in number and affect the skin, gills and fins of the fish. Some recommend salt addition to the aquarium water. However, it can cause more damage than it would benefit.

Symptoms to watch out for:
  • Fish holding their fins tightly clamped to the body
  • Fish swimming with the head near to the surface all the time
  • Fish swimming with the head up or down
  • Loss of color
  • Ragged fins
  • Scales sticking out or dropping off
  • A general loss of appetite and condition
Common diseases
  • Some of the common fish diseases are:
  • Ammonia poisoning due to poor water maintenance
  • Nitrite poisoning due to poor water maintenance
  • Öodinium – a fungal infection
  • Mouth fungus – a fungal infection
  • Cottonmouth – a bacterial infection
  • White spot etc.  
For treatment you can follow four methods:
  • Tank or Pond Treatment
  • Bath Treatment
  • Food Top Dressing (Usually Antibiotics)
  • Individual Treatment (Wound Dressing or Injection)

In some minor cases of external parasites, flukes, fungus, etc. a salt bath can assist the fish in healing better. This is in part related to the benefits of osmotic pressure regulation.


Stress is one of the major killers in freshwater aquariums.

Major cause of stress in a freshwater aquarium
  • Frequent fluctuations in water conditions
  • Tapping on the tank walls
  • Poor lighting
  • A bad mixture of fish where one of the fish bullies the others

Filtration and Cleaning


Freshwater Aquariums should be cleaned on regular basis to enhance longevity.

Cleaning a freshwater aquarium
  • To start off the cleaning process turn off all the electrical accessories.
  • Follow the tank and electric accessories manufacturers’ instructions carefully while initiating the cleaning process. Do not use any disinfectant, soap or detergent to clean the aquarium. These chemicals can be toxic for the inhabitants.
  • Clean the filter pads or compartments. If the filter has two or more media compartments, clean only one at a time so that the nitrifying bacteria population does not diminish.
  • While cleaning the biological filter do not use hot water, rather use cold de-chlorinated water.
  • After the cleaning process gets over restart the filter. If you see bubbles are still trapped in the canister filter, restart the siphon. Then turn the power on and place back the aquarium cover.
  • Cleaning the outside of the aquarium is as important as cleaning it from inside.


There are three main types of filtration for freshwater aquaria.

1.       Biological Filter
  • It eliminates toxic wastes such as ammonia and nitrites. Ammonia and nitrite are staple wastes in any biological setting. Both of them are highly toxic for the freshwater fish
  • A biological filter does de-nitrification of aquarium water by converting nitrates into Nitrogen gas. Nitrates are produced by action of nitrifying bacteria on the nitrites
  • These filters also help maintain oxygen level through aeration using air pumps and Water current using power heads, internal power filters, circulating pumps, and spray bars from canister filters
Types of Biological filters
  • The most common type of biological filter is under-gravel filter. It is placed under the bed of gravel.
  • The reverse flow underwater filters are more effective because they utilize water from the surface of the aquarium, which obviously has more oxygen. Filter pads should be checked and cleaned every two weeks.
2.       Mechanical Filters
  • These filters are used to keep water clear and free of debris
  • It removes the particulate matter from aquarium canisters using the pleated cartridges and power filters
  • The power filters force water though floss to remove the impurities. Many under gravel filters also act as mechanical filters and collect the debris in the gravel
  • Diatomaceous earth filters are special type of canister filters that can remove the particles that are as small as 3microns
  • Some of the powerful varieties can also remove harmful bacteria and algae blooms
  • However, they clog after sometime so they need to be cleaned regularly
3.       Chemical Filters

They take care of the chemical quality of the aquarium water.

The chemical impurities usually get dissolved in water so the mechanical filters are unable to remove them. This is where chemical filters come into action. They can remove any sort of coloring, odor or chemical impurity.

Types of chemical filters
  • The most common types of chemical filters are the active carbon filters. They are part of canister and power filters.
  • They have porous active carbon that traps the chemical impurities in the minute pores. They can remove copper, ozone, chlorine, antibiotics, some dissolved proteins and carbohydrates, iodine, mercury, cobalt, iron, methylene blue (a common medication), malachite green (another medication), sulfa drugs, organic dyes, and many other elements and compounds.
  • Here it is important to note that if you are mediating your freshwater aquarium you should first remove the active carbon filter. Peat is used to bring down the pH and reduce hardness of water for species that prefer “blackwater” conditions.
4.       Other types of filters

There are several other types of filters as well. Some of the most common ones are:

a. Foam Fractionators or Protein Skimmers: Large stream of small bubbles is passed through a column of aquarium water. The proteins and other organic waste adhere to the surface of these bubbles and get removed from the aquarium. They prevent the harmful organic chemicals from entering the nitrogen cycle thus lowering concentration of nitrates and preventing effective oxygenation of water. However they also remove trace elements like iodine so they should be carefully used.

b. Ultraviolet Sterilization: Water is passed through UV rays, which destroy the harmful bacteria, algae and parasites.

c. Ozone treatment: Ozone is a strong oxidizing agent. Thus, when it is passed through aquarium water it oxidizes organic pollutants and kills harmful organisms. However after the treatment the residual ozone should be eliminated because ozone in water is highly toxic for fish.

d. Siphon Hose: A siphon hose is needed for water changes. Siphon hoses are available in a range of sizes and designs: from inexpensive hoses to long hoses used for both emptying and filling.