Pectinea dying!

[Hooberminch]

pH 8.1,

Nitrate 3,

Phosphate .05,

Alkalinity 8,

Calcium 460,

Magnesium 1380,

Salinity 1.026

Some chalice corals have receded as well. Torches, acans content. Montipora bleached but acropora happy. I spot feed biweekly.

Tank has been set up for 10 months and has been stable. Nothing has changed recently. Pictures are 6 weeks apart but most of this happened over the past week.

Alkalinity has slowly been going down from 9.9 to 8 over the course of 4 months, only thing I can think of. Any recommendations? I haven’t done any dosing yet, I usually just manage stable parameters with water changes.

 

[andrewkw]

Is the gyre behind it blasting it? Nothing in the parameters look like they stand out. A slow 4 month change in alkalinity is not a concern in the least. Do you run carbon? If you don't I would give that a shot, and if you do I'd change it out as it may help remove whatever is causing the issue.

 

[Hooberminch]

I’ll plop in a bag of carbon now, thanks! It has low to moderate random flow

 

[Hooberminch]

Big boy is getting fat again, thanks for your help!

Added new carbon, lowered flow, reduced lighting, increased feeds, did 20% water change, removed all magnets