Honestly, I don't know what it was. Like I have mentioned. I do 10-12 day water changes, my numbers are all within spec, went and got a calcium test kit, calcium is good, alk is on the low end, but it is consistent. The only thing that I have had trouble with is the heat. I think it got pretty high while I was gone. It killed my arrow crab but everything else suprisingly is thriving. I am just happy my sps are re coloring. Right now my temp swing is 77-80. not to bad. And 77 is only since these cool mornings have come about(my tank is in the garage, and I haven't had the heater or air on out there this week).