This is correct based on the life cycle of Ich and velvet as well.. Each 'spot' - can produce a lot more - and rapidly the aquarium is very highly concentrated in parasites.Someone said earlier to me that when the parasites disappear they come back 2 times worse if not treated properly using copper. I do really hope it works permanently for you though! Definitely suggest vitamins in his food as that seems to work well too. Other than that i can ofcourse give you more advice from my experience but since the ones before that failed with the ich and im also taking my advice from experts its better to ask them haha, I dont want you to do the wrong moves too yknow.