Advice needed on filtration for a fish only system

[W0terMoist]

I've had a reef tank for a few years now and want to get a second tank housing just fish. I have a standard 20 gal tank that I want to convert to saltwater. Could I get by with a quality, oversized HOB filter that has two chambers? One side can be filter sponge, and then the other side can hold bio balls for instance. Or is the requirements for fish only systems as stringent as they are for reef systems? For reference, my reef tank is a 45 gal AIO with both hard and soft corals. The back of the AIO is full of bio balls, filter sponge, and a skimmer.

 

[CasperOe]

I've had a reef tank for a few years now and want to get a second tank housing just fish. I have a standard 20 gal tank that I want to convert to saltwater. Could I get by with a quality, oversized HOB filter that has two chambers? One side can be filter sponge, and then the other side can hold bio balls for instance. Or is the requirements for fish only systems as stringent as they are for reef systems? For reference, my reef tank is a 45 gal AIO with both hard and soft corals. The back of the AIO is full of bio balls, filter sponge, and a skimmer.

Technically you can get away with water changes only, depending on what you add to your tank! HOB will work for you just fine- you can even consider a good canister filter if you have the room - and the discipline to clean it as and when required!

Tailor your filtration to what you have in the tank. Input should match output so to speak. A HOB filter and a HOB skimmer (if needed) will do you just fine.

 

[Mr. Mojo Rising]

rocks and flow are always the main biofilter in a saltwater tank, I run 2 tanks with just rocks and flow and weekly water changes.

If you want to add mechanical/chemical filtration, its up to you and it is an added benefit, if you keep it clean enough to avoid it becoming a nitrate factory.