I am using
API. I need to start proof reading my posts better. I meant to say less than 20 ppm.
He is definitely a he, he has long tail fins. He was bright blue with a bright orange tail. Now he is gray with a light orange tail.
I just checked on him again and now he has a small hole that is a little bigger than a pencil lead next to his eye. Is this HITH? I can't tell if it's that or where the other male got into it with him. Originally there was supposed to be 3 females and 1 male but I ended up with 2m 2f. I have never seen hole in the head before and most of the pics I've seen of it don't look like what he has, plus I see that it mainly stems from poor water quality. I gravel vac weekly and do 25% water changes, so I can't see how my water quality is poor and as I stated previously all my other guys are doing great.
Any ideas

??