Rohdactis Mushrooms

[Forge77]

Few months ago bought a nice Roh mushroom frag. After it had been in my tank for a few days all the mushrooms open nice and big and afew even started spliting.
About a week ago they all closed up and haven't open. One is clearly not doing well as it's melting away. The other seem to be fine, they just don't open.

I have tried moving them, diferent flow, more and less light, but no change.

Water is ok, nitrate are up a little, around 20, but everything else is right on. All other corals and even other shrooms are doing great.

Any thoughts.

Could the one dying mushroom be hurting the whole rock. If that were the case though wouldn't the corals around it be effected too?

Also there's a slimy grey sponge growing on the rock. It's a fast grower, could that be affecting them.

Thanks

 

[crabbejoe]

20 is pretty high for nitrates, try to get it below 10.

 

[thetrueclown]

When was the last time you did a water change?

 

[Forge77]

Working to get the nitrates down. The tanks a little on the new side so it's still balancing out. I do 20-25% WC every week with RO/DI water and Seachems reef mix. Last one was Saturday. I don't add anything else.
As of last test the trates were around 10 so there falling bit by bit.

It turns out the one I thought was dead is spliting into thirds. The others I don't know. They just don't open.

What about the spong? Could that have anything to do with it?

 

[Forge77]

Here's a few shots of my tank.

The Rohdactis

Other mushrooms

Whole tank shot