Whats wrong with my coral?

Thanks for the help. I have cutback on my PhosBan flow to slow down the reduction of phosphate removal.

I have not started biopellets yet, until
I get my corals back to health my build has been put on hold.

 

Should should probably test more often, or at least refine your testing procedures for more consistency and accuracy. I heard once the perfect test is the best test. In al lseriousness, I bet the issue are from the phosban cleaning the water too fast and this is how your acros are responding. It doesn't seem like a big shift, but it might be enough of a shift as you went through old phosban, to gfo, to alot on new phosban in a short period of time.

 

+1 You do a really good job of keeping your parameters stable given such a small water volume but the rapid drop in PO4 and slight ALK swings are to blame for this one in my opinion. The corals affected are a bit touchier than the other corals in the tank so that could be why you are having the issues primarily with these corals.

 

Both of you are most likely right, I hope everyone recovers and I can mark this down as a lesson learned.

 

Update of the corals tonight:

 

So is this a bad flat worm? I found it on my coral plug.. :-/

 

Can't say yes, but can't say no either. It definitely could be.

Google "acro eating flatworms" and comb through the first dozen or so images; there's some pretty good ones there.

 

I did, there was only 1 and I didn't see any eggs on my Dingo or GARF.

I have notice no more tissue loss and colors seem to be coming back.

 

That almost looks like more of a stomatella

 

Really? That's a snail, right?