I've had my barbs for 1 1/2 years, and kuhlis/sterbais for a year. I didn't QT the barbs since they were the first fish I got and had no problems. I QT'd the kuhlis/sterbais by waiting a month in the qt tank, and they didn't show any signs of disease. One of my barbs has some weird growth on his tail that's only on him, and noone else. It looks like something white is attached to his tail, maybe 1 mm in size. He's eating, and hasn't changed. My question is this: I'll be transferring the fish from a 75 gallon to a 20 gallon for a day or two until I move the 75 gallon to the new place, and was wondering if it was worth it to treat with PraziPro for a full week. A week should also be enough for an parasites in the tank to die off I'm assuming, or would I have to sterilize the tank too?