Pipe organ coral dying

[jlmiller1057]

I bought a beautiful green pipe organ coral frag about 4 months ago for my 90 gallon and now it is down to only 3 polyps and only 2 of which have been opening up within this past week. I have been dosing regularly. My calcium is just over 400 and my dkh is 9. My nitrite, nitrate, ammonia, and phosphate levels are all at zero. I have an octopus skimmer and run purigen in the sump. I have two strong and bright led light systems on top and circulation pumps running. I can't figure out why it is dying! At first I had it on the top of my rocks and it was doing well. Then it had a huge die off until I started supplementing more. Then it started coming back and about 5 new polyps appeared and now they have died off again. I've moved it around three times in hopes it will like a certain spot better than the last. I just moved it to the sand bed thinking maybe it was too much light at the top even though I have read that the green ones like more light. I am determined to save it so does anybody have any suggestions that could help me bring it back?

 

[jlmiller1057]

This is what it looked like then vs. now.

 

[wireefman]

High light and flow has worked for me in the past... no phosphates as algae clings to that coral like no other

 

[Salt Kreep]

Is that pipe organ hanging in there?

 

[Muller]

With my pipe organ it seems that if bristle worms can get in thru the bottom of the tube they are done for most likely eating the coral. But I have so many new heads that they replace the older ones the newer ones are also a different colour. I have mine almost on the bottom of my tank and they are loving it there. About 19" from T5 HO. They are growing towards the light so I moved them to more light and they stopped opening for a week. Once I moved them back they opened back up in a day. This spot they like is lower light with lower flow.
Now I have read in some places that depending on the colour they are they will like more or less light/flow. I hope you haven't lost your yet.

Alk 8, Cal 450, Mag 1450-1500.