Can a Canister Filter Sit Next To Your Fish Tank?

In Aquarium Filtersby PaulK

So you’ve decided to go with a canister filter for your aquarium and you’re not sure how to set it up correctly. This post will cover where to put your canister filter and other common mistakes to avoid so you can get the most out of your filter.

Where to place your canister filter

According to the manual on the Fluval FX4 and FX6 and the Marineland C series, canister filters must never be placed above the water level. Canister filters are designed to be gravity fed or they will not work properly. The reason is you need to be able to siphon the water from the aquarium down to the filter. It’s much easier when you have gravity on your side.

The maximum length of the hose should not exceed 6.5 feet or 2 meters so you cannot place the canister filters too low. The hoses should also be straight from the aquarium to the filter itself with no slack or loops.

Minimum distance below the aquarium is 20 cm and the maximum is 150 cm for both the Fluval FX4 and FX6

For Marineland C series the below aquarium range is:
C-160: 20-60 inches
C-220: 24-60 inches
C-360: 32-60 inches
C-530: 32-80 inches

Remember the longer the distance to and from the tank, the more the internal impeller motor has to work. You want to minimize that so the motor lasts longer and more efficiently pumps the water throughout the filter and aquarium.

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Proper Hose installation

In order to prevent leaks, the hoses must be cut cleanly (no jagged edges) and attached all the way into the canister fitting securing them firmly with the clamps. If you secure the hoses too loose, they may leak because you will have gaps. Use a razor blade or garden shears. If you secure them too tightly however, they can crack causing leaks as well.

The intake and output hoses should be just long enough to reach the canister filter and the fish tank with just a little slack. The longer the hose is, the more head pressure is created and the harder your motor has to work. That means your gph cycling will go down and your canister filter will not be as efficient at cleaning your water.

Media Setup

Some canister filters start at the bottom and some start at the top with the water flow. The first filters that the water should hit are your mechanical filters. Preferably, coarse, medium, and fine in that order. Next should be your biological filtration and then any other chemical filtration you may use. The reason it should go through your mechanical filtration first is to clear out any particles and muck that can clog up your biological filtration.

Trapped Air

Sometimes air will get trapped in the system. This will cause the canister filter to not run efficiently and lower your gph. In order to prevent this, make sure your hoses are secure. You may need to rock the filter back and forth to force the trapped air out.

Canister Motor

The internal canister motor must be installed properly as well or you will hear a rattling noise in the unit. The motor cannot pump the water through the unit efficiently which results in less gph of water cycling through the fish tank.

Improper Maintenance

You should clean your canister every 6 months or so. At that time you should replace your mechanical filters and rinse your biological filters with aquarium water. If you use tap water, you will kill all the beneficial bacteria that you have built up. Not good.

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