Help keeping sps

Going to stay at 76 for now, I have noticed some more movement in the sand bed as well, hard to tell for sure but looks like birds nest had some extension today
Have been watching your poll and general seems to be 76-80 but the high said would like cooler but lack or chiller or ease of maintaining it is on the higher side

 

I have a similar setup, only I have MH's. I see temp swings on my tank from 79-83. Livestock seem very happy.

 

Now I can't say I have an answer, but I do have a similar experience. I have an 80 gallon setup with a 40 sump, refugium, Vertex omega 150, GFO and carbon reactor. About 4 months ago, my sump leaked and I had to take it offline. So now, my tank has been running sump less.

I only have about 65-70 gallons of total water volume. No skimmer, but I added a hang on back filter to remove large organics.

Strangely, my tank looks better than it ever has. It even looks better than the 125 I transferred everything from. I could not keep any SPS before - I was barely able to keep a green Birdsnest alive. Now, I have a few random SPS frags and small colonies. I'm not good with names, but I have a pink milli, green slimer, a blue tenius, some random green acro and a few others. They all have great polyp extension and have put on noticeable growth and new stalks.

Of course, I've also changed up my WC routine. I used to perform 30 gallon water changes monthly. Now, I only change 5 gallons every 1-2 weeks.

 

Maybe water is "too clean"?