Sorry to hear Mark.

Not sure if I understood what you meant about Zeo? If you meant that it didn't do a whole lot to prevent RTN then I would agree, I tried in vain to use Zeo as a mechanism to prevent inexplicable SPS losses but it did not make a difference. Water looked fantastically clear and PO4 and NO3 were completely zero, but coral losses were exactly the same before and after.

Unfortunately this is the nature of SPS. Sometimes they just kick off for no apparent reason. :( Hope that it's just the one colony for you and not a 4 year nightmare like what I've had to deal with (I wouldn't wish what I've been through on anyone!!)

my comment re: Zeo was in response to Skimmin's suggestion.

I'm not using Zeo or other and unsure if it would make a difference anyways and your experience seems to imply such.

That's why they call it RTN (RAPID Tissue Necrosis)

this is an every summer occurance, heat waves come and people report loss. the best way to prevent summer RTN is to buy a chiller. I used to swing feom 78 to 85 all the time with no problems but when I started getting up to 88/89 then I would have problems, and at 104 you lose your whole tank:neutral:

My chiller kept the temp swing to 2 degrees all year and no more problems

Steve

Have the tank on a controller connected to a heater and evap fan. Sample the temp every 5 sec, average for a minute then log the max/min (and average) for the hour.

over a 78 day period going from the lowest low, to highest high the difference was only 2.6°C, with the standard deviation hour to hour of 0.3°

Not thinking the temperature.