Mushroom problems :( Please help

[dani]

1 1/2 months ago I got 2 nice rocks with mushrooms from saltwaterfish.com
Those shriveled to nothing and altogether disappeared
I guessed it was maybe the cyano in my tank. The cyano is under control and the water parameters are better.
5 days ago I got a rock with 7 super nice hairy mushrooms and now 2 of those are shriveling up. I am afraid the same thing will happen with this rock as the other 2.
Any ideas what could be wrong?
I have no problem with the plate coral and suncoral in my tank. Tank is 90 gal, Current PC lighting, temp 80.1, ph 8.1, nitrates 20ppg (down from 40 a few weeks back and continuing to decrease with water changes and vacuuming), Calcium 400

 

[flower]

Could it be chemical warfare?? Try charcoal in the filter, see if it helps. Mushrooms usually don't like too much light.

 

[dani]

I will try some charcoal.
I'm also thinking maybe they are not getting enough food.. I have a naughty red spotted sandperch that steals food from my sun coral (I now cover it when I feed it) and the batfish & clownfish steal from the plate coral ...