all quarantine really means is i watch the fish close and don't put them in with my other fish, i always keep my feeders a month before i use them, and most of the time i'll feed them jungle anti-parasite and anti-bacterial foods.
and i still think you're gonna need to go ahead and get a bigger filter, the sooner the better, the better your water is, the faster your fish will grow and less likely to get sick.
he had $25 a piece marked on the tank, but he told me if i wanted them to take them, i gave him a large green terror, jack dempsey, and a pair of hondurian red points not too long ago.