Brown growth on birdsnest

[Taylor]

I will take another picture next time I see it, probly be back in a few hours. I've been blowing it off my green birdsnest 3-4 times a day. It's a thin drk brown stringy substance, it is only affecting the birdsnest. Started with some frags I had of GBN then moved on to the main colony. One frag was Completely skinless in a few days. The substance isn't even that thick. The tissue seems to disolve away from the tips down about 1/4" a day. It was effecting the purple tip Monti frags but not anymore. Monti caps are all good. Lps are perfect. The substance is only on the green birds nest, not the sand, not the rocks, not the softies.

I'm treating it as if it is dinos even though it has no bubbles and it's not in enough quantity to get a sample without letting it build up and kill the coral faster.

My big 3 have been stable for weeks. I added an ats a month ago. My nitrate went from 5 to 2 to undetectable and phosphate went from .07 to .04 to .02. I consider to have bottom my nutrients out from over scrubbing, I dosed nitrate and took the ats down from 10 to 1 hour at night, also scraped it clean.

8.1 alk auto dosed 6 times a day
450 calc
1500 mag
78f apex
I have 4 acros as well, all tiny frags, one is growing well with huge polyp ext. The other three have some extension.

I'm going through a bit of a rough patch right now. I was in the middle of planning a 180 excitedly when my new wantanabei pair showed signs of velvet 2 weeks into quarantine, the fish that was with them died already. They look on there last leg. Now im loosing frags of BN that I told friends they could have for there tank and now loosing my only real sps colony.

 

[Taylor]

2 hours later, brown film already appearing again.

 

[29bonsaireef]

The BN must be in rough shape from something else in the water. Once the tissue is thin enough and the coral is no longer at peak health, algae can start to grow on it. You're most likely dealing with a cyano or dino type. This stuff can really be detrimental to BN colonies. The drop in nutrients could be the cause. I would try to get your params back to stable, and get as much of the algae off with a powerhead or turkey baster. Looks like it still has a chance at this point.

 

[Taylor]

I wanted to update on the issue in case someone finds this thread searching this issue. The issue was low nutrients and somekind of cyano/bacterial or maybe diatom growth. My nitrate was undectable and phosphate was very low. I have never had them so low, due to over lighting my new algea reactor I presume. Anyways I lowered the lights on the algea reactor to 2 hours at night from 16 or 18 and fed very heavy for a week and noticed my nutrients climb slowly. After this and about total of 2 weeks the brown growth subsided and I broke the tips off and growth has resumed very well and all frags bounced back as well.