Monti RTN overnight, no clue

[ojonas81]

So got some issues I can't pinpoint. Got some very unhappy corals and my Chili Pepper Monti decided to RTN overnight. See picture below.

Checked all parameters last night and nothing that stands out that could have caused it from what I can tell.

SG: 1.028 (slightly high but has been around this for a long time.
Alk: 10.81 (working on getting it down to around 9. Has been high for a long time.
Ca: 600+ with Hanna checker. Red Sea kit gave 430
Mg: 1400
PO4: 0.09 (same for a long time)

Any ideas on what else could have caused it?

 

[markalot]

Can you get a closer picture? Has it been slowly losing flesh until last night? When I had monti eating nudis the population built up to the point that they could destroy a monti overnight.

That said, your parameters look out of wack. Calcium 600+? I'm not sure that's possible.