I have my 2 motoro rays in a 125 gallon. I used to have oscars in there so there was lots of poop in the sand. They disturbed all the gravel and made a ammonia spike. The ammonia level was at .75 ppm. I did a 80% water change at 1 30 am. I just finnished the water change and the ammonia is still the same. I hope my rays are not dead in the morning... what can i do?????