Can a coral shade itself?

I'm posting this quick, I have class soon lol. Here is my birds nest. It is grafted to my birds of paradise so I reallly don't want to lose it. It started merging about 3 or 4 months ago by accident.

It is shading itself, and for a long time, it was just whiter on the bottom. It turned brown very recently. I can't be sure when, maybe a few days ago or less. Maybe even today. The top is fine along with other frags from this colony in the tank. It looks like it could be spreading. It looks like something is growing on it rather then it just turning brown. Here are pics. I will take clearer pics later I am just in a rush! 3 hour class, I am posting this rather then eating. Coral>Food

Top:

Bottom:

 

Yes, the bottom can be shaded and die when the colony gets big enough. This is just a natural part of how reefs grow though. The old parts underneath will become part of the rock structure if your tank, and help get your sps closer to the light.

Michael Rice
Marine Engineers Aquarium Blog
Sent from Tapatalk so excuse my poor English

 

Yup, as Mike said.

I've got a basketball sized green birdsnest that has done this; first the entirely shaded tissue went white, then it sloughed off. That part of the coral is skeleton now; rest of the colony is healthy as ever.

You've got a little algae growing on it now; shouldn't be problematic unless you've got nutrients to fuel it.

 

Last I checked my nitrates were zero. And I am running GFO. PO4 test kit is terrible, asking for hanna checker for holidays. Using RODI with filters less than a month old and zero tds. Feeding little enough that my fish look thinner. In process of changing T5's, and running them only 8 hrs per day. No supplements/additives. Salt is reef crystals. Running chaeto in sump/fuge w/ 24 hr light cycle - it's filled with algae. I honestly don't know what else to do.

Thanks guys, good to know that this nice coral isn't dying (totally). As or a few hours later last night it didn't look like it had spread at all. The branches of this birds nest are so densly (is that a word lol) packed together, I can't imagine how any light would get through.. I figured mabye the coral is living as a whole and just getting its light source from the top. Guess thats not the case. I would hate to lose this!

 

I really think you're fine here. Algae loves to grow on skeletons, regardless of how clean things are.