[mtfabel]

5 degrees is quite a bit for SPS but they can manage if its the right 5 degrees. I know that sounds weird. If it goes from 78 to 83 then its bad but if it goes from 80 to 85 its not as bad. Now you're sitting there thinking thats still 5 degrees either way. There hae been studies done that say that corals can handle higher tempetures if the low temp is a little warmer. I had the exact same problem and after I read that, I turned my heaters up to 80 degrees and still had the 5 degree fluctuations but had no more problems with my SPS. On the same token I have added a fan since I made the first correction I just talked about. The fan allowed me to keep it within 2 degrees in a days time. Its still better to avoid that much swing if you can.