Fish Tanks – shape, size and volume

Saltwater Aquarium Setup

Now that you have decided to become a fish owner, it’s time to think about as aquarium tank. Fish tanks come in a variety of shapes, sizes and volumes

There are now a wide variety of aquarium sizes, shapes and materials on the market. Depending on the fish tank, this influences the number and selection of fish or living beings, plants and other furnishings. Some fish species need a large water surface because they prefer to stay in this region. At the same time, sufficient depth promotes swimming comfort and thus the quality of life of the fish. In this article I will introduce you to the optimal aquarium for beginners and other interesting aquarium shapes.

On this guide you will find information on:

What is the right aquarium size for beginners?

The answer will surprise you: aquariums of 100-200 liters or more are suitable for aquarium beginners!

This may sound strange, but large aquariums are much easier to maintain than the smaller ones. If there are problems with the technology or with the water values, larger fish tanks are much less sensitive and more recommendable for aquarium beginners. The animals that can be kept in this aquarium size are also better suited for beginners.

Which aquarium should beginners buy?

A recommended aquarium for beginners is this popular complete set with basin, LED lighting, aquarium filter, heater and matching aquarium cabinet.

Thanks to the coordinated components, the aquarium with a capacity of 120 liters guarantees an optimal start to the aquarium hobby.

You can find more details and the current price for the 120L aquarium on Amazon.

This LED aquarium set is also available on Amazon with a capacity of 200L.

Aquarium size – table

Below is an explanation of what else is important for the right aquarium size for beginners.

Aquariums are offered as 60 cm, 80 cm, 100 cm or 120 cm fish tanks, for example.

The numerical value indicates the length of the aquarium. A standard aquarium is 80 cm long and usually available in the dimensions 80 cm x 35 cm x 40 cm (LxWxH).

Very small fish tanks, so-called nano aquariums, have been a trend in recent years. These are available in stores from 20cm in length and are suitable for lower organisms such as small shrimp, crabs or snails.

The following table lists the most common aquarium sizes:

Fish Tank DescriptionDimension/SizeGlass thicknessVolume GrossVolume Net
20 cm20x20x25cm0.4 cm12l9.1l
25 cm25x25x30cm0.4 cm20l17.3l
60 cm60x30x30cm0.5 cm54l50.5l
80 cm80x35x40cm0.6 cm112l105.0l
100 cm100x40x40cm0.8 cm160l148.0l
120 cm120x40x50cm1.0 cm240l220.0l
150 cm150x50x60cm1.2 cm450l413.0l
200 cm200x60x60cm1.5 cm720l657.0l

Aquarium shapes – from rectangular to round

Which aquarium to buy? In order to make this decision easier for you, I will introduce you to the different aquarium shapes, explain the respective advantages and disadvantages and give you a purchase recommendation.

In addition to the classic rectangular aquarium shape, there is the corner aquarium, the panorama aquarium, the stylish Nano Cubes and other aquariums with five and six corners. Narrow wall or column aquariums are visually attractive, but usually not recommended. It is hardly possible to keep the fish in a species-appropriate manner, as this form considerably restricts the freedom of movement of the fish and offers little or no retreat. The vast majority of aquariums have glass panes. A large plexiglass aquarium is significantly more expensive and allows very individual shapes.

If you want to buy as a beginner an aquarium, suitable aquariums complete kit. These are the aquarium itself, the lighting, the heating element, the filter and other accessories.

The whole thing is optically perfect with a matching aquarium cabinet.

Rectangle aquarium

The classic among the aquariums is certainly the rectangular aquarium. When it comes to buying an aquarium, it leads most beginners to this timeless fish tank shape. Due to the rectangular shape, the aquarium can be easily integrated into a living room.

It is easy and perfect to clean with an algae magnet because it has no round or sharp corners.

This beautiful aquarium for beginners and advanced users is available in different colors and optionally as an aquarium with a base cabinet.

Panorama aquarium

Thanks to the rounded windshield, the Panorama Aquarium offers a great insight into the underwater world. Thanks to the elegant design of the curved front pane, it blends in well with any room.

The removal of algae from the curved windshield is not a problem if you make sure to move the algae magnet or sponge from left to right.

I can recommend this panorama aquarium set to you. The aquarium cabinet offers enough space for all aquarium accessories.

Panoramic Wall Mounted Fish tank with tropical freshwater

Corner aquarium

The corner aquarium is perfect if you want to buy an aquarium that is very space-saving and should also offer a great look. It fits perfectly in every corner of a room. Since a corner aquarium is very deep, the underwater world looks particularly impressive and realistic!

The cleaning of a corner aquarium is a bit more complex, as the fish tank is deeper and the corner aquarium is not as free in the room as other aquariums. The pointed corners of some models are not so easy to reach with an algae magnet. My tip: just use a coarse filter sponge. The corners can be cleaned easily with this.

If you want to buy a corner aquarium as a beginner, I recommend this complete set with a matching base cabinet.

The Juwel corner aquarium has recently also been available as an energy-saving LED aquarium. You can find more details about the LED corner aquarium and the current price here on Amazon.

How to build a corner fish tank

Nano aquarium

Nano aquariums are the most modern aquarium form and have found their way into the aquarium hobby with the keeping of small shrimps, crabs and snails. As the name suggests, it is a small aquarium with a capacity of only 12-30 liters.

The mini aquarium trend originally came from Japan. The art of bonsai was transferred there to the underwater world, which is known as aquascaping. The stylish Nano Cubes are a real eye-catcher and still find space on every table, shelf or chest of drawers.

There are special tools for cleaning a nano aquarium.

Our tip: Drain some water, and then you can go into the aquarium with your hand and a small piece of sponge without the water overflowing. You also clean the mostly round corners of a nano basin with a filter sponge.

You can find the best nano cubes and lots of information about mini aquariums in the article “Nano Aquarium: The Ultimate Guide 2020″.

fish tank
Nano fish tank

Calculate aquarium volume

As an alternative to the specification in centimeters, fish tanks are also often specified in liters. The classic aquarium for beginners (80cm) corresponds to a 112l aquarium. When calculating the aquarium volume, it is important to determine the gross and net volume of the aquarium, for example to correctly dose medication and to know how many fish can be used. It can also be used to determine the weight of the filled aquarium. It is therefore important to be able to calculate the aquarium liters.

How to calculate the gross aquarium volume:

Aquarium length in cm X aquarium width in cm X aquarium height in cm / 1000 = gross volume in liters

Example: Calculating the aquarium size for a 100 cm fish tank:

100 cm X 40 cm X 40 cm = 160l gross aquarium volume

You can calculate the net volume of an aquarium by subtracting the glass thickness of the aquarium basin:

Aquarium length – 2xGlasstärke X Aquarium width – 2x Glass thickness X Aquarium height – 1xGlasstärke / 1000 = net volume in liter

Example: Calculate the net aquarium size for a 100 cm fish tank with 0.8 cm glass thickness:

98.4 cm X 38.4 cm X 39.2 cm = 148.1l net aquarium volume

Professional tip: If you want to calculate the swimming space free for fish, you have to determine the effectively usable aquarium volume. In addition, the filling level (water level up to the upper edge), the gravel height and the remaining equipment (roots, stones, plants, heating element, etc.) of the aquarium must be calculated.

You can calculate the filling level difference by reducing the aquarium height in the formula above by, for example, 3 cm. That makes 136.88 liters. The aquarium gravel reduces the aquarium height in the formula by another 8 cm. This is how you calculate how many liters of aquarium gravel you need.

Conclusion: For our 100 cm or 160 l example aquarium, the effectively usable aquarium volume is therefore 106.6 liters.

If you subtract the estimated volume of the remaining furnishings (10l), we come to ~ 96 liters that the fish have as free swimming space.

Rule of thumb: gross volume – 40% = free swimming space for fish