Oh yea, for sure night time dosing. Sorry for any misunderstanding. To clarify, I dose around 2500mls of Kalk from 10:00pm-10:00 and dose Triton Core 7 the opposite 12 hours. Overnight, I’ve dosed both PH based, as well as constant drip (3.5ml/min) on that volume of kalk. The drip gives me a downward trend PH, from mid 8.3’s down to 8.2 at its lowest before lights come on again. But I can dose ROUGHLY that same amount +/- and hold a PH line at 8.30-8.32 when it doses from a 30ml/min doser. I’m just trying to lock in the better way to do it since I don’t have a large variance in amount dosed PH based. My PH always climbs to almost 8.40+ during the day when I’m dosing 2 part.If the goal is to prevent the nightly low, which is a reasonable goal, I'd dose only at night, spread out through the night.
If the goal is to boost calcification rate, then dosing during the day may actually help that more since higher pH may boost calcification, which seems to mostly happen during the day.
I don't think trying to keep the pH at 8.30 to 8.31 is necessarily going to work. If the pH is 8.3 at 11 AM, I think there's a good chance the pH will go higher even with no additions.
I also think that trying to see a visible difference between a reef tank tank at pH 8.2 and the same reef tank held at pH 8.3, or varying between pH 8.2 and 8.3 may be challenging.