Help!! Acan bacterial infection, or something else?

[YMAonthisreef]

Hello,

To begin:
Salinity: 1.25
Alk: 8.3
CA: 470
Mg: 1400
No3: 2-5ppm (was 60 - 80 ppm a couple weeks ago)
Po4: .22

32gal Biocube running protein skimmer and a little ball of chaeto on the back fuge area.

So a few weeks back I started feeding Oyster Feast, as the LFS has a beautiful LPS tank and said he feeds it daily. I wasn't adding much, but just a small squirt a day.
Fast forward two weeks and all of my Acans, some of my favia, and now one of my bowers started to shrivel up. The Acans began having massive die off and very quickly. When I checked the NO3, it had gotten up to between 60 - 80 ppm. I started doing daily 10% water changes, and started turning on the light on the fuge daily instead of every other day. Now the NO3 is around 5 ppm. The Acans still seem very unhappy, and some still seem to be slowly dying off. I will post pictures, but I am wondering if maybe the high nutrients have started a bacterial infection. This is the first time experiencing an issue like this, and am very upset as a lot of growth died off in a matter of days. Does anyone have experience around this issue? Any help will be greatly appreciated.

 

[Bo.]

How many days has it been with your nitrates back to lower levels?

 

[YMAonthisreef]

It’s been a little over a week. But now other LPS are starting to display the same. Different Favia that were not showing any signs are starting to recede and now some zoas are starting to shed zoo at an alarming rate

 

[Noahdoe]

Hey this same issue seems to be occurring to my acans and damaging my other LPS. Did you figure out what was wrong?? Thanks !!