Frag tank skimmer?

[KingTriton]

So Ive started a SPS frag tank 20 long and was wondering if I need a skimmer. I won't have any fish. Ive heard large WCs will work, but what exactly is considered large and how frequent since I want to promote stability? Thx

 

[klesel]

Yes I wouldn't do any tank with out a skimmer especially a Sps think it's such a valuable piece of equipment.