Red monticap dies overnight

[JMartin104]

90g reef
PH: 7.9 - 8.1 (fluctuates)
Ammonia: 0
N02: 0
N03: 0
P04: ~.06 (fluctuates slightly)
Ca: 480
Mg: 1500
Sg: 1.026
Kh: 8 (forever)
Skimmer, refuge with chaeto

Here's how it normally happens. My perfectly happy and healthy looking red monti gets what looks like a bleach spot. Within 24 hours, the entire thing is white and pretty much dead. Nothing is left but a solid skeleton. I have not been able to identify any changes that could have caused it. No other corals seem to be affected.

This has been in my tank for 1 year. It started out about the size of a quarter and died at about the size of a grapefruit. It's about 16" below 250w MH - same as the green monti.

This has happened 4 times over the past 2 years (only to my red monti).

I have a green monti in the same tank that has NEVER had the issue. Why would one constantly die while the other remains healthy? The reason I ask is because if my water parameters caused the issue, wouldn't it impact both?

I love my red monti but I'm not finding any answers. Before I try again, I want to determine the cause.

 

[viper12775]

I have the same problem with montis whatever causes it never hurts my acros I've never figured out the reason

 

[jgraz]

Did you inspect the skeleton. Any chance of Monti Nudi's

 

[jdhuyvetter]

Check your kH with a different kit.

 

[rovster]

Did you inspect the skeleton. Any chance of Monti Nudi's

Nudis wouldn't wipe it out that quickly. Ask me how I know.....

 

[incognitus]

Something releasing an attacking chemical to water can do that. I´ve lost mine when pulling up caulerpa taxifolia form a near rock.

 

[JMartin104]

But why the same monti and not the other? I will try a new kh kit but I don't think that's it.