Quarantine Setup

Hello,

I resarted a reef ( 3 month old ) 90 Gal reef. Right now I have 1
Flame, 1 Yellow, 1 cup coral, 2 leathers, 3 shrimps, 1 feather duster
and star polyps, everything is happy. I put B-Ionic every morning. I
have a Bac-Pak Skimmer ( I moved it from my old 30 gal. I know it is
not big but I figuered it would be better then nothing). It is setup
with plenum. I have 3 Hagen 802 for movement. Presently I have 4 40
watts fluo. I also have 4 110 VHO but the my IceCap ballast is being
repared. BTW, I know some complained about the ballast but I like it
very mutch.

Now for questions:

I would like to add a hypo tang but this time want to be more carfull
in adding fish. I want to setup a small quarantine tank. I tough of
getting a 10 gal. I presently have a small aquaclear 300 running on my
90 gal, I tought of moving the sponge from this filter to the
quarantine for bacteria. What do you suggest for setup: Size?
Chemicals? Filtration? Time I let the fish in? Lights or not?
Anything that I dont know of?

Thank you in advance