with ICK you need to treat the entire tank, however many fish show signs. the ICK bug (it has three stages) is, in the water, in the substrate and in/on the fish.
The fish with ick has only a few small dots and is also swimming and eating fine. So no matter what, i must treat my whole tank even if others are looking ok and no spot?
Will the temperature method work? Raise to 30 degree Celsius and keep it there for two weeks. I'm afraid salt or any medication will affect my corys...
Please help...
I would hike the temp up, when you medicate. but, no, in my view raising the temp, and not medicating, will make things worse.
you already know salt is a no no.(I'm sure some will say "my cory were fine". i prefer to listen not those with much more knowledge) but there are medications around safe for them.
treatment will take longer though as you use half dosage. you will also need to buy a product that can be given so.
if you don't mind, I'll take a little time to explain something of what ICK is. understanding this, will help when treating your tank.
ICK has three stages (they all have specific names, but for this purpose I'll call them 1,2 and 3)
1, is the one you will notice (spots on fish) technically the final stage, this one burrows into the fishes slime coat and, eventually, creates more ICK stage 2
2, drop to the substrate to mature. (technically the first stage) but unseen by you
3, a free swimming form, they go off looking for a fish to infest. again unseen by you.
I'm sure you can see, now, why you need to treat the entire tank.
treatment will need to be in several stages. this is because the ICK is only vulnerable during its "free swimming stage". so, you will have to wait till all stages have cycled to know you have irradiated the problem.
in your case it will need, in my view, 2-3 treatments a week for 2 weeks. remember you are using 1/2 dosage.
I hope i have explained this clealy. but if you are struggling (with my drivel, lol), just give me a shout here.