Do Fish Tanks Need Lids?

Aquariums are an ever-increasing pastime, yet when there are individuals who come to begin their first fish tank, they are often torn between tanks without lids and tanks without. While there is a price difference between the two, and they obviously appear very different from each other.

There is that lingering question that is often asked. 

Do fish tanks need lids? In the purest form, no, there is nothing to say a fish tank must have a top. However, there are benefits for them having one, and there are benefits for tanks not to have one.

Before purchasing either kind of tank, here is all the information you need to help make a better-informed decision on whether you want a tank with a lid, or you decide to have one without.

Benefits of Having A Lid on Your Fish Tank

While a lid is not compulsory when you have a fish tank, it can be very beneficial to have one. They stop kids from dropping things into the water and other pets entering. They also help prevent water splashing out of the tank and reduce evaporation.


Evaporation is the conversion of water into vapor. But we forget it can happen to an aquarium. When there is no lid on the tank, evaporation occurs very easily, meaning the tank loses water quickly. This evaporation leaves a higher concentration of mineral deposits in your fish tank.

A lid helps avoid the necessity to refill the tank more frequently because of evaporation, and thus there won’t be an increase of the salt deposits.

Jumping Fish

There are many kinds of fish that like to swim around the surface of the water. While these do so, they may seek the opportunity to catch small insects, or they are the kind of fish that frequently jump when startled.

Some fish, like hatchet fish that typically prey on flies swimming close to the water, naturally try to jump out of the water.

Falling Objects

The lids on your tank will help prevent any foreign objects from dropping or being thrown into your tank. It is possible that nearby objects may fall inside your tank. These can harm fish, or worse, damage your tank. Additionally, kids are fascinated by fish tanks and like to watch things sink to the bottom of the tank.


Pets, particularly cats, enjoy putting their paws in the water to drink. If they spot a fish swimming, they will try and catch it with their claws. If they don’t manage to catch your fish, they will scare them, and they may knock some of your equipment into your tank that can break or kill your fish.

Fish Tank Smells

When it is time for your tank to have its water cleaned, you can find there is an odor rising from the water. Once you have a lid on your tank, the gases will remain inside the tank and not spread into your room. Open tanks don’t suffer from this problem

Types of Fish Tank Lids

You may have heard the terms cover, hood, and canopy and asked yourself if they are all the same. The issue is which is best for your tank. Here we explain the different types.

Glass Lids

Glass lids will fit seamlessly into the aquarium to help prevent evaporation; they are easy to clean and longer-lasting than plastic lids. Most of the glass lids are made of two glass panels, which are connected in the middle by plastic hinges.

When buying glass lids, it is advantageous to be sure they are supplied with a vinyl backing that allows you to tailor cut-outs for filters and other accessories.

If you wish to add illumination to a glass cover, you need a separate lighting strip that is compatible with the cover.


The hood is the section that covers the lighting fixture. They can come with plastic lids which cover the aquarium. A single hood which covers both the aquarium and holds the light is usually cheaper than separate tops and lighting units.

A few drawbacks are they don’t fit as good as glass and thus allow more evaporation. Add to this, they become brittle and can break. 

Cheaper hoods usually have low-quality light fittings.


A canopy is a decorative top that provides a cover for the tank as well as housing one or more lights. Canopies are not a necessity as they are more of a decorative top that typically matches the tank stand and adds a finished look to the room it is in.

Pros of Open Fish Tanks

Although having a lid for a fish tank is beneficial in many ways, not having a top can also have its benefits. Much of it comes down to personal preference.

Here are some of the plus points for aquariums without lids:

  • More lighting options
  • Easier to feed the fish
  • Can have plants that grow above the water
  • More lighting can get to the plants
  • More mounting options for filters, heaters, etc.
  • Rearrange the tank accessories without needing to remove the lid

Open tanks are increasingly popular for the above reasons, and they just look more beautiful. There is nothing to catch the eye, and you can see every inch of the tank. Even the water from the pump can cast rippling lighting effects onto the wall.

Maintenance of Open Aquariums

As much as aquariums look pleasing to the eye without lids, they do need a little more effort to care for than ones with lids.

Because there will be considerably more evaporation, you will need to top up your tank with fresh water daily or at least on a regular basis before the salt accumulation becomes too high. This needs to be with demineralized water from a RO (reverse osmosis) system.

Because it is just water which evaporates, even with water from the faucet, there will be a buildup of minerals in the water. You can see these over time if you don’t clean your tank by the hard white substance that forms on your glass.

This shows you have hard water, and when it comes to cleaning, you will need cleaners to remove this hard scum, or your tank will no longer be a pleasure to look at.

Do Tank Lids Help Over Night?

Aquarium lids will help with night periods. Like humans, fish are on a cycle of day and night, and some fish require varying numbers of hours of light in the day.

Most fish need 12 hours of light, and also space to sleep. In the day, natural light from the sides of your tank is more than enough for your fish and the ecosystem. During the night, the sole light source will be your light.

If you keep this light on for extended periods, there is the chance of algae growth. With this, and there can be upset with the inner harmony of your tank. You can see, this is one of the things which makes tanks appear dirty.

You can turn the lights off during the night to avoid all of this, and thus giving your fish a chance to rest. However, it is at this time, fish can be startled by noises outside the tank, and when they are most likely to jump. 


While there is no one argument to use a lid on your tank or not, there are plenty of things that can lead new tank users in both directions.

While there is as much about preference as anything else, a lot can come from the type of tank you are aiming to have and the kinds of fish you are hoping to have in your tank. Add to this, the location in your home where your tank will sit.

If it is just on the side of the room, then a lid may be a good option, however, if you have a dedicated area where your tank can sit, then it can be a better option to do without a lid to enjoy your tank from every side and as well as the top. As long as your fish are happy and are safe, that is all you can ask for.