mystery frag tank

[lilrobb]

So the mystery around my frag system continues.

A staghorn frag that was doing just peachy for about a week (noticeable growth, good color, polyp extension) RTNed within 3 hours today.
Temp is stabilized with a chiller now 78-79F
Alk: 11
Mag: unknwn
Ca: 520
Ph: 8.3

Calcium reactor running - so mag shouldn't be anywhere off the chart.

I had the same issue before and blamed alk, pH and temp on three other occasions.
Full tank reset, now with 135gal sump incl 60gal refugium and still the same issue...

Any input?

 

[stoney1118]

sry to hear that bro, its so frustrating! sometimes it just happens, im sure there was a cause but maby its just something that cant be determined. ive had a few corals randomly rtn in the past. could anything have stung it>? sweeper tentacles??

 

[misu]

turn off that reactor, you said the simpler tank doesn't kill anything

too much light? you were also asking about it

I have a salifert mag test kit if you want to test that too

 

[ralph atl]

what test kits? (alk might be higher?)

phosphates? nitrates?