SPS 911
 

been trying to introduce some sps frags into my 150W MH 34G tank
i have them on a rack mid way, waterflow is moderate yet i have noticed they are turning white and PE minimal with stringy substance shedding off the coral itself
my phosphate is 0 nitrate minimal (5-10) with elos test kit
dkh is around 8 tested with a hanna tester
What is causing my SPS to regress ??

well..nitrates of 10 is pretty high for SPS.

What about calcium? magnesium? what other corals in there? chimical war? fish ?? parasites? If they all do this, then it is clear that there is something in your tank, either water parameter (copper?) or something attacking them.

Do they shed skin fast or slowly and starting from the base?