Order some prazi pro online at marinedepot.com or bulkreefsupply.com. Don't risk it. Stringy white poop hanging on the fish is a good indication of parasites. The treatment won't harm the fish especially since you said it is eating really well. Sometimes I have noticed prazi can make them eat less. But you want to make sure, otherwise if your fish does have parasites it will slowly waste away while you think it is doing great. Best advice you can get.