Ah for cryin out loud..my Typhoid Petco fish not only caused ich,I think it brought it gill parasites. Some of the other fish are are rubbing gills. First sign of disease in 2 years.
So I bought Kordon's Rid Ich+ Its 240 gallons and tablet cures are out at 1 per ten gallons, only10 per package and I might need more.... So I turned to Kordon after watching the Fish Doc on Youtube treat those illnesses with formaldehyde. Kordon has that with malachite green also. A $12 Bottle is plenty for me to use three days in a row and have plenty for "next time".
It turned the water blue,not green,for an hour of so..then cleared up. They say,not harmful to plants. It's a three day treatment partial water changes..vacuuming the substrate for ich eggs. Water changes and vacuuming I had already started doing.