While setting up a new tank, many hobbyists wonder if it’s better to have an open aquarium or use a perspex or glass cover. Both solutions have advantages beyond stopping fish jump out of the tank water. This article will look at both options to help you make the right decision.

Why are the covers useful?

Glass covers, glass tops or glass lid, whatever you call them, the aquarium cover has major advantages. Below is a comprehensive list of reasons why a fish tank cover is important

Temperature fluctuations

Glass lids help to reduce the risk of any unwanted temperature fluctuations. Your aquarium water stability is essential, especially when housing delicate fish species.

Prevent evaporation

A cover helps to reduce the evaporation of your aquarium water. As water evaporates, moisture is released into the air. The more evaporation, the more humidity. Too much moisture can lead to dampness and mold forming on nearby objects.

Jumping fish

A problem across the entire world of fish keeping is fish jumping out of their aquarium. Everybody wants to prevent fish from leaping to their death. Aquarium hoods or plastic lids can prevent fish from jumping out. Glass lids are especially nice if you do not wish to have a hood.


An open-top aquarium will undoubtedly attract the attention of cats. Why risk it? Enjoy an open tank’s aesthetics by adding a glass top, Creating the illusion of a sleek topless aquarium while preventing your curious friend from causing any unwanted issues.

Contamination from the outside

An aquarium with no lid may look good. However, lids will prevent things like cat hair, dust, and other natural air pollutants found in the room from falling straight into your fish tank.

Keep things tidy

An aquarium hood is an excellent place to hide wires, cables, and light fixtures. When aquariums have hoods on top, make sure to use a plastic or glass lid to prevent water splashes from damaging the hood or any equipment inside.

Covers for tanks with a large water surface

It is also commonly accepted that the cover is necessary for large, several hundred-litre tanks. Aquariums of this size have increased water evaporation which can cause high humidity in the room and create the risk of fungus or mould on the wall around the aquarium, especially in old buildings and spaces without good ventilation. The owners of smaller aquariums have more comfort and freedom of action here. Moreover, tanks with intense evaporation are more likely to have problems with water parameters.

While there are many good reasons to use an aquarium cover, many people prefer open-top aquariums. A common reason for this style is to accommodate plants and hardscape which emerge from the fish tank water surface.

Topless fish tank – yes or no?

Everything comes down to your personal choice. Open aquariums are by far more aesthetic and, done correctly, can vastly improve the surroundings. Live plants can grow above and beyond the water surface. No lid also allows us to admire the water surface from the top down. Anybody who knows us knows just how much we enjoy our top-down views.

It is important to know that with a coverless tank, water evaporates quicker than from an aquarium with a lid. This requires regularly topping up the difference during water changes.

So, what fish is the safest choice for the open tank?

It is worth accepting that surface-dwelling fish are not a great idea. Also, nervous species with a tendency to dart around when stressed will more than likely jump out of open aquariums.

DIY mesh coverings offer protection against fish jumping.

Mesh Covers

If you really don’t want a covered tank and plastic lid or even glass lids that don’t appeal to you, there are mesh covers available in kit form. These DIY covers can be fitted to almost all aquariums and offer protection for your fish that may attempt to jump. Why they are not 100% they can give some defence against this problem. Water will still evaporate and they do not offer any cover against dust or heat, a mesh aquarium cover is used on an open tank as a minimum.


To sum up, the choice of whether the cover is needed or not remains in the hobbyist’s hands. Everything depends on the stocking and external factors. Nevertheless, having the aquarium lid is very useful when we have jumpy fish and small children.

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