Ok so yesterday’s tests ALK: 7.0, PH:7.9, Cal:438
Todays tests ALK: 7.0, PH: 7.9, Cal: 424.
now who knows how accurate the Hanna checker is for calcium I’ve heard they are not super consistent on numbers. Definitely consumption from corals or maybe Derasa clam. I’m probably being dumb about this and chasing numbers on something everyone is dealing with on a daily basis but thought I’d ask the experts. My thoughts are to go with sodium bicarbonate for the increased alkalinity and a short PH drop. Would it be a good assumption to dose directly to the tank until desired ALK ( of course slowly). Record the drop in alkalinity over a period of time to get a pattern of consumption then start adding sodium bicarbonate to my auto top off?
It's fine other than I thought you indicated you wanted higher pH.....if so don't use sodium bicarbonate.
Personally I would not add to topoff water unless using something like calcium hydroxide. A cheap doser works fine.
Also make sure you dosing calcium and magnesium also. Calcium is normally needed in nearly equal amounts to alkalinity. Magnesium can be tested and dosed less frequently but needs to not be forgotten. 2-part solutions are going to only add alk or calc and need dosed separately. Kalkwasser adds both. Something like allforreef adds calc/alk/mag/other trace elements all at once....but won't have a pH boosting impact.