quarinteen

I on the weekend bought three upsidedown catfish, and one Clown loach, I
put them in a cycled unused tank as a home for the cats and quarinteen
for the CL. Where I got my fish I trust as they themseves quarinteen
their new arivals, but I thought it would not hurt. My question is how
long should I keep him in there it has been 5 days since I bought him
and no signs od ICH my main consern, he eats well and has even grown
about 1/5 of his size now sitting at about 1.75". Another question will
he have a problem when I put him w/ the other CL's that are about 3.5"?

TIA