Be careful with the FX5 if you go there.
The FX5 pump is in the bottom of the canister. This creates 2 problems.
1. Solids from the tank will settle in the bottom and clog or damage the pump rotor assembly.
2. The fine filtering media is in the bottom basket, which makes it more of a chore to clean and replace fine filter media.
In your other canisters, such as Eheim and Rena, the pump is on top, which when all the solids settle out, they are at the bottom of the canister and not getting into the pump. And when you go to clean out your fine filter media it is right on top, and easy to change out.
Most of my canisters I replace the fine media once a month, the other media is rinsed& re-used maybee every 3-4 months.