My LPS corals have been slowly receeding/dying. It first started with my bubble coral then favia and now my hammer, frogspawn & rics are also slowly receeding/dying. All of these corals have been in my tank for over 2.5 yrs. I do water changes and maintenance monthly. Please let me know your thoughts on what is going on here? The alk,cal,mg & phosphate are all testing accordingly. It is a 72 gallon that has been running for over 3 yrs. I have posted pics to show the problems. Thanks!