Bleaching green birds nest?

[Guinness]

I've had this birds nest for 4 months. First 2 months were good, then the polyps turned white but the skin stayed pink/ orange. Now the polyps are turning green again but the skin turned white. It's always kept good polyp extension and has almost tripled in size from the 1.5" frag. It's in a biocube 32 with stock leds and return pump. Pp4 and sun sun wave maker pointed at each other with pp4 set to else for flow. Any thoughts?
Tank params:
Nitrate undetectable with api
Phosphate less than .25 but detectable with api.
Just ordered a better phosphate test.
Cal 470
All 7.7 dkh
Mag 1290
Have to pick up a new ph kit.
I dose b ionic mag alk and cal 10ml every other day which raises alk .7 .
Here's a photo of the coral and a fts.

 

[Guinness]

Lol the pictures seem to have gotten away from me. First time using my phone to upload.

 

[Guinness]

Also there is no stn rtn or any other tn.

 

[Som1else]

Looks like they might be starving, I dont see many fish and your tank looks almost too clean to me. Try adding some reefroids or something to increase your nutrients. What are your phosphates and nitrates at?

 

[lbacha]

If you have .25 phosphates and no nitrates you may want to dose some nitrates. Not only will it help lower the phosphates but it will feed the coral as well

 

[Guinness]

Just ordered reef roids. Would stronger lighting help?

 

[lbacha]

I started using reef roids/reef chili and reef energy and my colors improved drastically

Before (a month ago)

Now (the pic doesn't do it justice but the body is now a deep pink/purple with light blue tips and green blue polyps)

 

[markalot]

Turn down the lights, unless you really think you don't have enough, they look like they are bleaching due to too much light. Go mostly blue and dimmer if you can.

Never use a PH kit to measure PH. Either get a meter you can calibrate or don't worry about it. The only safe way to fix PH issues is to either bring in air from outside or run skimmer intake through some CO2 absorbing media. Any chemical fix will spike KH and kill your corals.

Personally I would start dosing two part daily rather than every other day to keep KH more stable. A .7 rise will be fine for some corals and not for others.

 

[Guinness]

I don't think it's bleaching from too much light. It's a biocube 32 with stock lights. It lost the color on the skin over months. I thought bleaching from light would happen faster. I think the 0 nitrate is the answer. Should I start dosing with spectracide and start feeding reef roids or just start feeding. I prefer not to change 2 things at once.

 

[markalot]

I don't think it's bleaching from too much light. It's a biocube 32 with stock lights. It lost the color on the skin over months. I thought bleaching from light would happen faster. I think the 0 nitrate is the answer. Should I start dosing with spectracide and start feeding reef roids or just start feeding. I prefer not to change 2 things at once.

I think you're right about lighting, I'm not sure stock lights are bright enough but it may also be the nitrate issue. Personally I would feed with Reef Roids before trying Nitrate dosing, but I really don't know which will offer the most improvement. Reef Roids will slowly raise PO4 and N as well, at least I assume it will since I doubt every last bit is removed via export.