Rookie sump question...

[jasond]

Hello all, my first post here on canreef. Great site, lots of excellent info!

Currently I am running a 20gallon with about 20 lbs of LR, couple softies, and a couple small fish/invertebrate. Seems to be going not too bad, however after 4 months, already have the itch for a bigger tank (should have known!)

Here is my sump question. I will probably upgrade to a 50-60G tank, with sump and maybe refugium. I am thinking I would use my current 20G for my sump as I am told this should be sufficient. What I am curious about, is why, from what I have read, do people not seem to use filters (such as the fluval), with a sump? I realise you can, but people dont really. Do you put carbon in the sump, or don't use carbon at all? Same with phosphate removal media? So for starters, sump would contain Protein skimmer, LR, heater & UV? What else?

I have dont lots of searching, and there seems to be no perfect way of doing it, just looking for some opinions!

Thanks in advance,

Jason