New Coral Frag Tissue Recession

[MitzSD]

When I get new coral frags they recede to the point of death and then there is just a small piece left and they slowly grow back from there. I waited 6 weeks before getting more corals to see if I still need to "mature" the tank. I just got some frag packs from WWC and it's happening again. I attached 3 photos to show the bleaching/recession on the outside areas and the last one is of my lord just to show he is healthy. I updated a video that I took to show some people my pistol shrimp but later on it shows the whole tank. I have pineapple sponges showing up everywhere and Coraline all over so it seems like everything should be doing well. My early placed LPS are slowly growing but nothing too fast. Acans on the sandbed have started to add heads and are big and fluffy. I keep trying SPS but they all die, can't even keep a birds nest. I have read and researched but can't come up with anything so I'm asking for any input.

Here is my tank setup:
Red Sea 750 XXL 10 months old
AI Hydra 26HD's at AB+ to around 110% on the UV, violet, royal, and blue. Green and red at 5%. Cool white at 30%
3 Ecotech MP40's. Two in upper part running various modes at 65-75% and one on lower area running 50-60% reefcrest. I don't know if the flow is too low???
Running chaeto with a Kessel H380 at night but it is barely growing. I am getting algae all over in my sump so I know if have some nitrates/phosphates.
Running a carbon reactor but stopped GFO 2 month ago to try and "dirty" up.
Auto water change 1 gallon per day, was doing 3 gallons per day but dropped it to try and "dirty" up water.
I scrape the glass every day so there are nitrates and phosphates but nothing showing on tests.
I broadcast reef roids twice per week and amino acid every 2 weeks.
Daily feed PE pellets
2-3/week frozen mysis or Rod's, switch every time.
Salinity 35.5 with Apex
Alk 9.4 with Hanna
Calc 1420 with Hanna

 

[ndrwater]

1st knee jerk reaction is two fold.
The UV settings on your lights might be cooking the corals a bit. Start low in the tank and once acclimated, move up slowly to your desired location. This gives the corals time to acclimate.
2nd, your ALK, while not high, is a bit higher than most corals sellers keep theirs. Alk burn is pretty common, and sounds a lot like what you are experiencing. Again, slow and methodical acclimation is the key here.
Once established, the corals will do just fine at 9+ ALK.

 

[Katrina71]

I was gonna say start everything low.