Hi all. About a week ago, I lost a few Pleco fry, and soon after many, MANY more had passed. I was devastated. I had assumed I had an ammonia spike, so I did several water changes, and afterwards, ammonia tested at 0. Still, I lost plenty of Plecos. At the time of writing this, nearly all of the fry have died. Yesterday, I noticed a white patch on the tail of one, and assumed it was columnaria, which I had experienced with neon tetras before, so I dosed API general cure. Today, I noticed all of the plecos have nearly translucent tails, and here are some photos. Any advice would be appreciated. My parameters seem fine, with 25ppm nitrate (with plants), 7.6 ph, and at 76f.