Well I was not going to share this but if there is something I can do I will if not too late. Last week I was doing a water change of 35 or 40 percent and next day all rays breathing really hard for days one ray still is I am surprised she is still alive. Water test good for all the basic test ammonia, nitrite ect. I have another tank with captive pups doing just fine water seems to be testing the same. I know my hardness is high but always have been and my ph from tap is 7 but my tank is always low like 5.8. only thing I changed was I added some new bio media by marine pure that day but I have been checking water and this has not interrupted my water quality. There has been a lot of different things happen in a sort time to this tank. I acquired a new ray that I could not quarantine but this ray has been in captivity for years. Since I got here some how I lost cycle to the tank or the tank could not handle bio load so there was a ammonia spike for prob 3 weeks all rays ate the whole time ect. I know they were not happy but there was nothing I knew what to do and was surprised it was such a long recovery. I did placed a fluval fx 5 that was running on another tank. Next thing to happen was new ray had something on her above her eye I thought anchor worm but it fell off and healed so I don't have a clue. Ok so back to the current problem new rays will not eat still breaths hard other rays still seem stress but are not breathing hard anymore and are eating very little. Here is the thing that's is killing me is I got the tank back in order with the ammonia prob and what ever was on the ray fell off and cleared up meanwhile all rays were eating infact the new ray ate like 15 shrimp out of my hand the day before this current prob. I am sure I left out a lot of imfo but it is hard to put everything on a thread. I feel really bad that this is happening the worst is knowing that the new ray is showing no signs of recovery and not eating at all witch to me means most likely her kidneys are shutting down.