Steve, I guess my question comes about by the fact that for the first 3 or 4 months, every piece I had displayed full PE during the day. Now, 905 do not, with no obvious reason, other than the one water change I did with different salt (which affected my alk). Ok, somewhat obvious perhaps, but until I get my alk back to where it was, unproven hypothesis
So the tank has matured, the zeo system has had a chance to develop (or over develop with my dosing schedule), lighting is more than sufficient, feeding has been constant, no fish additions at the before/after point, so it's a bit of a mystery. Not so much a concern, but more a puzzle that I'm curious about.