I added my 8" motoro to my big tank with my 15" B. Juruense, 8" Cichla, and 10" Ornate Bichir 4 days ago. Everything has been fine and the acclimation went well with the ray eating as soon as he hit the water. This morning around 10 everything looked fine when I left for work. Well I jsut checked on him again and a solid inch of his tail has turned white! 
I had experienced some tail rot withj my retic but it progressed very slowly and only a little at a time. This however is a sizeable portion of his tail. Water params are good, but my nitrates are on the high side (80-100ppm) so I have been doing about 25% water changes daily and added live plants in the sump to get it down.
I am terribly bummed as my ray did have a nice long tail and Im sad as it may not heal.
My main question though is; could this be a fungus or a bite from one of my rays larger tank mates?
I had experienced some tail rot withj my retic but it progressed very slowly and only a little at a time. This however is a sizeable portion of his tail. Water params are good, but my nitrates are on the high side (80-100ppm) so I have been doing about 25% water changes daily and added live plants in the sump to get it down.I am terribly bummed as my ray did have a nice long tail and Im sad as it may not heal.
My main question though is; could this be a fungus or a bite from one of my rays larger tank mates?
