I run a canister on my 55g and all I have in it is biomedia rings and filter floss. If the need arises you can place carbon and GFO
for phosphates in it too. The only problem with a cnaister is it has to be maintained frequently or it will just accumulate waste and nitrates will soon follow. I run a fx5 on my fw
125g and its more than sufficient.
As far as the skimmer and UV
, I would consider a skimmer but not the UV
. The skimmer can take out excess organics from the water if you need it. Being as your fish only the skimmer you could probably add at a later date. But it will have to be a hangon type since you don't have a sump, which will cut your selection down a bit. A sump would be ideal if you can swing it, if not you should be fine as you are.