I've done 3 50% water changes but can't get the ammonia to go down. Anybody have any idea why I have ammonia considering that the only things in here are corals and a couple of caribsea life rocks? My ammonia is 1, nitrite is .5, nitrates are above 50, and phosphates are also high. My tank has brown algae now. On the bright side, I can get a cuc now.