my birds nest needs a little help, this is the most senior sps coral in my tank so there is no way im gona let him die. i have noticed that the base is starting to turn white and is losing some polyps. what is up???? he is still pretty small and he is halfway down in the tank under a 175 watt metal halide. my calcium is 160 ( im gona let that drop a little back to 150 or 140 ) and my alkilinity is 10 dkh. i have not tested my other perimiters yet but they should be fine. i have a bag of phosphate remover in my sump that i dont think is exousted yet so what could be going on u think??? thanx for all help. :)