My chalice and other LPS dying!!

[BTP]

My two chalice's and other LPS are dying! There flesh seems to be receding from the edges and revealing there skeleton. The rest of my softy corals are flourishing and up until a few weeks ago so were my chalice's. I have a 120 gal reef tank with a 50 gal sump, plenty water flow and light. I feed my corals every other day and perform 20% water changes every other week. Anyone have any idea of what might be causing this? please help!

Temp-78
ALK-8.5
Cal-420
mag-1400
PH-7.9
Sal- 1.026

 

[donnievaz]

What are your nitrate and phosphate levels. They may be nutrient starved.

 

[djrice69]

No other corals near by stinging it?

 

[BTP]

I have undetectable Phosphate levels, but i have not tested my nitrate levels recently. The Purple and green hat looking like chalice was actually getting crowded and stung by my green sinularia leather and i relocated it, but the other are spaced plenty far away from anything that could sting them.

 

[Tab28]

As mentioned above nitrate levels. Your Alk at 8.5 your nitrates should be 5-10. For LPS to absorb nutrients. Softies can survive in about any water. So they are not a good indicator.

 

[BTP]

I will test the nitrates then, thanks for the help guys!

 

[john.m.cole3]

I was going through the same thing and decided to make some changes. Give this thread a read1
http://reef2reef.com/threads/corals-are-pale-wont-grow-shriveling-away-and-dying.263563/