All right, maybe this a stupid observation on my part, but I'll say it anyway. Isn't it somewhat natural to have some swing in your tank? Actually, a little swing helps everything.:mrgreen: Look at how we live-our air quality and many of the things we drink are harmful to us,(budweiser & crown royal, as examples) yet we tolerate them and grow accustomed to the variations, to an extent. I know that the fish, and to a greater extrent, the invertebrates, have much less tolerance obviously. But trying to keep everything perfect all the time seems like an impossible chore.
I know from years of freshwater that you can look a fish over and tell to a great extent if that fish is healthy and thriving.
Yotes swing of 7.8 to 8.2 doesn't seem harmful to his tank, I recently looked at the thread of his tank pics.
I know I'm still learning saltwater, but I'm just saying...