Canister filters are often the best choice for larger aquariums when you don't want to have a lot of ugly equipment inside the tank. They are also a good choice for large planted aquariums with carbon dioxide fertilization where it is crucial to keep the water surface from getting disturbed. The filter media basket system in a canister is very adaptable to many different types of media allowing you to tailor it to your specific needs.
Canister Filter Installation
Place the input and output flow pipes into the aquarium where they will be permanently installed. Sometimes a directional output or spray bar needs to be snapped onto the output pipe. Usually a pre-filter is included and needs to be snapped onto the end of the input pipe.
Place the canister where it will be permanently running and measure the length between the input/output pipes on the aquarium and the corresponding ports on the canister filter.
Cut the hose, which is usually included with the canister, to slightly longer than the measured length so that there is a little slack but no kinks or sharp bends that impede water flow.
Attach each end of the hose so that the input pipe in the aquarium goes to the input port on the canister and the output on the canister connects to the output pipe in the aquarium.
Fill the filter basket or multiple baskets with the manufacturer's recommended filter media or choose your own that fits the guidelines. Usually there is some type of floss that fits between basket layers or around the entire basket. Rinse the filled basket with water to remove any dust.
Place the filter basket in the canister in the correct orientation. Make sure the filter input and output pipes match up so the water can flow through the basket easily. The basket should fit and not have to be forced.
Fill the canister to the manufacturer's recommended fill level with dechlorinated or aged aquarium water from the same tank you will be connecting the filter to.
Dip the large O ring in the water to get it wet. This helps make a seal on top of the canister.
Place the wet O ring around the top of the canister; usually there is a groove it fits into or flange it rests on. At the same time put the canister lid on top to hold the O ring in place and lock it down or screw it in depending on the brand of canister you have.
Turn on the power and the canister should purge any remaining air. Check for leaks around the seal on top of the canister. Reseat the O ring if there is a leak.