Ammonia 0
nitrites 0
nitrates 20
30g
I have a rosy barb that has a crystal like speck on his fin. Is this Ick. It kind of looks like a piece of aquarium salt. I want to treat with salt. Meds are hard on the bio-filter. The problem is I have catfish. Can I treat the barb in a hospital tank or does the whole tank need to be treated. I also am planning to set-up a new tank and use this one as a donor, will the gravel and bio- media be effected?

I don't start treatment when I just see one thing on a fin. I would wait a couple of days and see if this amounts to anything first before starting treatment. Over the years I have often seen a dot develop on a fin, and then have it never develop into anything. Just my opinion, but at the moment I would take the wait and see approach.