Trachyphyllia Having Issues

I purchased a trachyphyllia about six weeks ago and there is a bleached patch that has been slowly expanding over the last couple weeks. I had a problem with Aquavitro Salinity salt and my alk was down around 4.3 dKH. I bought a new test kit and confirmed it was accurate. I already lost a huge stylo that I grew out from a frag to RTN and I don't want to lose this coral too.

I have raised my dKH to 9.0 over the past week but the bleached patch is still growing. I vodka dose so I don't want to go much higher. I also dipped it in CoralRx last Sunday. It still expands well at feeding time and happily eats if I target feed. The bleached area does not expand as well but there is no skeleton showing. Here are my current parameters

pH - 8.2
Ca - 400
Mg - 1350
dKH - 9.0
Phosphate - 0-.04 depending on when I check it
Nitrate - 0
Nitrite - 0
Ammonia - 0
sg - 1.025
Temp - 78

Any advice on how to proceed is greatly appreciated. I'm starting to panic.

Here are a couple pictures. Sorry for the white balance quality but I used my phone.

 

It may take weeks for the coral to recover from the alkalinity issue.
What is your lighting type?
Judging from the images the coral actually looks pretty darn good. Keeping feeding it and maintaining the water chemistry. You might think about changing salt mixes.

I would not start to panic until you do see recession.

Unfortunate about the Stylo, so frustrating, especially when you've grown them out.

 

I don't have any advice but I ran into the same problem with aquavitro and low alk. I have since switched back to reef crystals. Good luck!

 

Thanks for the advice. I have the stock RSM lighting still. 6 x 39 watt t5 fixture with 3 ATI Coral Plus and 3 ATI Blue Plus. I was initially trying to use up the rest of the bucket and just keep adding buffer but I think I might just give up and buy a bucket of Reef Crystals.

 

Thanks! I will be switching back as well.

 

I love aquavitro chemicals but reef crystals is the salt for me. The trachy looks good, just keep feeding and keep an eye on the params. Like corailline said, don't panic as there is no recession. My trachy has been stung badly twice in the last year and the areas were completely bleached and still made a full recovery. I can't believe how hardy that coral is.