I set up and old canister filter(Fluval 203) that I haven't used in years yesterday. I hooked it up to an established tank (125 gallon) that has a large sponge filter and an Eheim canister running on it. I am wondering how long it would take before the new/old filter (fluval 203) is ready to use on a small tank (about 5 gallons). I have 8 medium uaru one medium to large rhino pleco a few corys a school of small tetras and a few other small fish. With this bio load I am thinking it should take at least a week for bacteria to establish. Not sure. What do you think?