Running skimmer causing birdsnest issue?

[Llg]

I have had a green and a pink birdsnest now for 3 months. I have had good growth and great extension. I noticed yesterday that the green one has one side where the polyps are not extended and a few patches of necrosis. The necrosis may have been when the snail knocked it off down through the frogspawn to the sand. But this one whole side doesn't look good. I moved it lower in the tank today to see if that helps.

My pink birdsnest has a spot at the base completely missing. This could be from a hermit crab eating the algae, shadowing or something else.

I add a protein skimmer about 10 days ago and had been using just a refugium before then. The only other thing is that my alk moved from 9.3 to 8.8 and then back about 2 weeks ago. But I have had this degree of variation before in my smaller tank and it was fine in there.

It has been steady since. Is this related to the protein skimmer? Monti's, stylo, LPS and softies all look great and are growing.

Salinity 1.026
Nitrate 2.5
Phosphate .1
ALK. 9.3
Mg 1480
Calcium 480

 

[dedragon]

It could be from a drop in alkalinity or even microbubbles from the protein skimmer, but i suspect if its been growing it is probably blocking either flow or light to itself as birdsnest corals tend to do.

 

[Llg]

This side is direct to the light and the closest to the wavemaker. It was on the opposite side and a bit on the shade and when it fell, I moved it over to get more light.

 

[dedragon]

figuring out flow/light is hard with sps, sometime i find myself adjusting it every couple of hours to get right. When did this coral fall into the frogspawn and do you know how long it was sitting in the sand for?

 

[Llg]

It fell about 2 weeks ago. It fell sometime overnight, so I am not quite sure how long in the sand. I did dip in logo's yesterday as well just to see if that would help it.

 

[dedragon]

could be lingering effects, light/flow change or the alkalinity drop, best to keep it where it was espescially if it was doing well there, maybe increase flow a tad if you have a dc wavemaker. If it starts getting bad I would snip the dying branch and save the rest

 

[dedragon]

and parameters stable. I always do a 10% water change as well whenever things get upset just in case