Could you elaborate on this Geoffrey? I'm aware of this to a tiny degree but not sure what the impacts are.
It’s as @Nick potts stated @Courtneybst :
Windows open in the summer means less CO2 in the room, which means less of a PH drop which isn't good in a reef tank.
Did request the family all stop breathing so much as it’s hindering the tank… unbelievably got a cold reception with that idea. So selfish!
Winter tank pH fluctuates between 8.0 to 8.2 over 24 hours. Windows open this week been achieving 8.3 steady over 24 hours and an uptick in growth. Just a seasonal feature rather than a bug. It’s more that pH is steady which appeals.
Murdering the science here, but you preferentially want calcium combining with carbonate rather than calcium bicarbonate formation. Calcium bicarbonate will leave an H+ to get rid of. Locally, this additional H+ may leave fluid in the coral more acidic and make it harder/impossible to calcify. Outside, pH in part affects this outcome:
There’s also the balance of carbonates/bicarbonates in the water to consider depending on how you dose over time. Water changes are a great equaliser.
Using calcium formate as a means of calcium input helps preserve this balance. Also, unlike calcium acetate, calcium formate won’t pillage your o2. All For Reef is a pretty smart product if you think about it. Won’t carry you all the way with larger Ca/Mg/Alk demands bit it’s a great start as base dosing.
Anyway, gone off topic @Courtneybst , but that’s an elaboration as currently understood.