Bleaching. Help please?

[cmdmd]

This is the only coral that is bleaching in my tank.

Water

Temp 74.6-75.2

Salinity 1.025

API Kit

NO2 0

NO3 0

Ammonia 0-.25 (estimated, Looks like zero, but for all I know it could be 0.25)

pH 8.0 (I detected a change today, 2 days ago it was 8.2-8.4) I use API's "Proper pH 8.2" for buffer

Phosphate 0


Here's the photo.

http://s1034.photobucket.com/albums/a430/cmdmd/Bleached/


Any ideas?
I have some Phos Ban in a nylon bag in the sump.

Thanks for your attention.

 

[KeMo]

What about your calcium and mag ? Those kind of corals will die off if your do not keep all your parameters in check. Are you keeping other sps ?
What about your lights ?

 

[cmdmd]

Yes, I have another acropora and he is doing fine, growing pretty well, actually. I'll post photos tomorrow. Also, a bird's nest and a stag, I think. Calcium and magnesium...funny story there, I do not measure those, I was going to order kits, but I forgot . I guess this is a good lesson. I started adding a supplement I purchased at Foster&Smith, liquid reef ( http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=19751 ). First dose, today. I also add Microbacter 7 after a water change.

I haven't put my tank info on my footnote....I shall soon.

28gal JBJ HQL lights. System is 3 months old.

 

[wrott]

Looks like an A. tenuis. You should do several 50% WCs ASAP over next 2 days.
It has STN, so you should break off a couple of viable fragments and glue them to another piece of LR ASAP. In all likelihood, that tenuis is a goner, sorry.

You may need to increase the temp to 78-80F. This will benefit the acropora tremendously, along w/ GFO and carbon.

 

[cmdmd]

Ok, I'll see if there are any changes today and take action,