BigWyll

+1 on check the heater. Could be a small crack that doesnt effect the temps. Also, how do the snails look. My first indication of faulty heaters was there were no snails on the glass.

RODI water

I've blasted some of the harder to reach monster aptasia with boiling water. But beware It kills what ever you spray. So if its close to corals, it's not the best idea. The heat made the turkey baster a mini guiser so it's hard to control where it released.

In that case the sandbed never "settles." Simular to having active sand stirers in your tank. You don't have to worry about diatoms blooms on the sandbed, right? Just trying to figure out if I'm learning or if not, how far off course I am.

Question: isn't disturbing the sandbed like restarting a cycle? Whether it is 2" or 6" deep the surface is no longer th surface and the bottom is no longer the bottom so things living in the sand have to re-settle. That would give diatoms the opportunity to bloom while the live sand get adjusted to it's new environment, right?

I had the same problem in a 55 gallon tank. What I did was use boiling water to kill all the aiptasia I could see. Especially the larger ones. Then I put 8 pepperment shrimp to eat anything that may spawn from what I killed. My display has been clean every since. But then I noticed aiptasia growing in my sump. So now I do the same in the sump. Kill what I see. Let the shrimp handle the rest. The some of the shrimp in my display ended up in my sump so it worked out well. Another option is to cycle each rock in a qt tank with pepperment shrimp. Kill what you see and let them take care of the rest. I believe this is recommeded for using Nudibranch also. This will keep the shrimp or nudi safe while eating aiptasia

Wow... that's creepy. Just happen to me two days ago.