I noticed that my pleco was not eating or moving, I thought he was dead but when I looked closely I noticed he was still breathing. he started with this small white patch at his tail then it spread all they to his upper fin.he didn't move or eat for a week so I put him out of his misery. I'm just wondering if anyone knows what it was or what happened so I can avoid this in the future. my water levels are 0 nitrate,0 nitrite,0 ammonia,6.9 pH.water temp 78.
