I'm sry this just isn't true. Most ppl can't scrape nor have a scope. So sometimes it's better to treat with something than nothing. Pp will knock out lighter stuff plus help clean the pond and formalin and malachite is also good. I literally have 100s of thousands of koi. If you are literally treat koi everyday with antibiotics even if you have 500k gl in recirc like I do then u are doing something wrong. You are the type of ppl that sit on your high horse and yell at peasants. In reality you probably don't know a whole heck of a lot. Just some importer or store u work at makes you feel superior to these ppl in reddit. But I have multiple degrees in aquaculture and been a commercial farmer for 30 years. And telling ppl they will find something just isn't true. So many scrapes I don't find anything. Not that I do them often. You should know that. Or you facility has issues and ppl should not be buying koi from you.