I buffer to 8.3 and always keep it there. PH slides about, but as long as the alk is 8.3 and the mg is 1300, calcium stays in solution for my corals. Stony reefs are not the WHOLE ocean, but they are a slice of ocean where fishes such as we keep seem to like to be. I can't interview them and ask them, but they're healthy, don't have problems, eat enthusiastically and their aggression level is low, so I assume they're feeling ok.