ok filter method for 55g

[knorsk]

I have a 55 gallon and I already put the live sand/live rock in so a undergravel filter is out of the question. I don't know if I have space for a sump underneath only have about a foot underneath the tank. I was wondering if the hang on tank filter will be ok or if i should get a canister filter or some other method of filtration. Or I could run the 55g hang on filter w/ an old 30g filter also? I also have a skimmer that is ok too.

[Whys]

What you need is a skimmer and the liverock will do the rest.

Undergravel filters are no longer used in saltwater tanks and canisters are mostly only used for freshwater tanks. Some use canisters for activated carbon or GFO, but typically only hook them up for a few hours at a time, as these quickly get dirty and become nitrate factories. It is better to run these in a reactor, if you decide to use either at all.

[PRDubois]

Hang on Back or HOB - Protien Skimmer.
Since you have a 55gal - Get one that is rated for 100gal or more.

they are all rated low.