Help please coral bleaching

[mtnrunner]

90 gal mixed
MH and t5 actinic

I've lost a small mili coral to sudden bleaching in just two days.

Cal 445
Alk 9.9
Sg 1.024
PH 8.58 at 6pm
77 degrees

Started running mh for an additional hour this past Saturday, total mh time 5 hrs, actinic for 12 hours.

Added Ecobak 3 weeks ago, 1/3 a week to total of 250 ml in BRS reactor.
Run charcoal and GFO in BRS reactor.
Have doser for alk/ cal dose daily. Use b-ionic.
Dose korai color and Acropower too.

Weekly 16 gal water changes.

I've noticed pH creeping up after extending mh by one hour, usually maxed at 8.5
Then it returns to about 8.35 by morning.

Why am I getting coral bleaching? Suggestions?

 

[mtnrunner]

Bump.

Any ideas?

 

[Reefing Madness]

Got your Mag and Phosphate numbers?

 

[mtnrunner]

Mag 1350
Phos .03

 

[Pete polyp]

Do you feed them?

 

[Reefing Madness]

Welp only thing I see out of place that started the bleaching about the same time is the Ecobak. Try stopping that for a bit, see if it helps any.

 

[Pete polyp]

That could be the issue. From what I understand is that it takes a few weeks for pellets to work. Very well may have stripped all no³ from the tank and has caused the bleaching. Try feeding the you know what out of them. I have had lots of success in bringing back acro that were white as snow by feeding coral frenzy and reef roids.