Many aquarium owners find themselves wondering whether or not fish tank filters are waterproof. The answer to this question may seem obvious, but the waterproof credentials of a filter ultimately depends on the type of filter you are using. Generally speaking, you will have a clear idea of how waterproof a fish tank filter is by determining whether or not it can be submerged.
If your fish tank filter is a submersible design, it should be completely watertight. Other types of filters, such as those that hang on the back of the tank or are designed to be concealed underneath gravel are somewhat different. In theory, these filter varieties should also be completely waterproof, although you may notice some water intrusion over time.
Submersible Internal Fish Tank Filters
If you want complete peace of mind, it makes sense to invest a little more in a submersible fish tank filter. Otherwise known as an internal filter, these units are designed to provide specific areas of water within your tank with increased water flow. If your fish tank is home to a considerable amount of fish, they are definitely something to think about.
They can also be used in tandem with other types of fish tank filters to ensure water conditions are properly balanced at all times. However, this type of water filter will only perform well with tanks with limited water capacities. As a rule, any tank with less than 20 gallons of water will benefit from a submersible filter.
As this type of filter is designed to be fully submerged within the water within your fish tank, they are completely waterproof. With most internal filters, you will need to connect the inlet to an airline. When installing an internal filter, ensure the airline is properly secured as this will feed into an external pump. Any loose fittings here can compromise the waterproof credentials of your filter, with the potential for leaks and damage to your filter hardware.
Other Types of Fish Tank Filter
A hang-on filter is another option. These filters are positioned on the back of an aquarium and feed water through filtered material in the form of a cartridge. Although these are designed to be waterproof, the inclusion of filter material can cause you issues with leakage if you have not secured all components securely.
An under-gravel filter is another option. As the name suggests, these filters are designed to be positioned underneath the layer of substrate at the bottom of the tank. These pull water down through the substrate material, filtering out bacterial growth that might be forming on this base layer.
When using an under-gravel filter, make sure you have installed it correctly, with no housing exposed to the water layer. Although they are designed to be waterproof, they will struggle to cope with constant exposure to tank water without a layer of substrate protecting them.
