my sps frags are not doing well. no poly extension and one is going white from bottom up. almost as if it is deteriorating. i did 80% water change yesterday. i have a 75 gal display and 30 gal sump. the tank was established when i bought it but was not taken care of that well imo. i have had it since dec. i bought some sps frags about 2months ago. too soon probably, too late now. i ran my tests today and looked good. took to lfs to confirm my tests and looked good other than ammonia. alk 8, cal 500, mag 1400, nitrite 0, nitrates 0,phosphate. 25, salinity 1.025. ammonia .25 or .5. cant remember what lfs wrote down since i left it at the store. the phosphate from lfs was .25. if im doing my red sea test correctly, i am more closer to 0. everything in tank is ok other than the coral. rbta are fine, fish and other inverts are all fine. i have diatoms on rocks and sandbed. almost as if im cycling again but not sure why. would the ammonia be doing thism