My pepper corys are all getting sick, please help!

jack26707

I had four pepper corys in my 20 gallon fish tank, two have died. One of them had a red tail and the second had a red neck. The other two seem fine. If everything turns out okay I'm going to get another pepper cory in a few days. I put in some medicine, scrubbed the tank glass, rinsed off the decorations, and did a six gallon water change. PLEASE HELP! Thanks.

aquakid

Dont add anything new in yet. Id say wait at least a week or two before you add anything new just to make sure things are stable