Problems with Coral

[1Matthew]

Hi all! Haven’t been on the forum for quite a while. I have recently been having issues with my los corals. Corals such as my acans, one torch, and my candy cane

Here are some of my levels I recently tested:
Alk:8.6
Calcium: 420 ppm
Mag: 1350
Ammonia: 0
Haven’t gotten to testing phosphates but last time I tested they were at .02
I use RODI water, and Red Sea blue bucket salt.

 

[1Matthew]

I’ve also got some bubble algae growing in various places if that makes a difference