Canister Filter Problems

Canister filters are best for aquariums bigger than 20 gallons. They filter large amounts of water very quickly because the water goes through layers of different filtration material. But there are some disadvantages to using canister filters.

  1. Size

    • Canister filters are often as tall as their tanks to be able to hold a large amount of filtration media like charcoal, cotton wool or bio-balls. They can also be very heavy. Because they are so large, they can also be more expensive than other filter types.

    Appeal

    • Canister filters are often very unattractive and detract from a home's decor. The filter may need to be hidden or placed entirely underneath a tank stand with doors that conceal the canister.

    Expert Advice

    • Since a canister filter moves large amounts of water quickly, it can remove medication for fish placed in the tank water before the fish have a chance to absorb it. Before putting medication in a tank, first remove all carbon filter material, which is what soaks up the medication.