In big tanks I run a CaRx but in smaller ones I use a doser. I only dose minor elements manually.But to answer your question... I probably shift .2 throughout the day. No clue how much that matters to corals, before I used to dose most alk at night for ph boost, had .7 swing throughout the day. But it would test the same at a given time. I don't correct based off one day of lower consumption, I check that everything is running properly(flow,aeration, room co2, lights etc). If it continues to decline for 2 or 3 days I will back off doser until I get consumption to climb for 2 or 3 days then adjust again. Calcium reactors were much more popular back when they didn't test that often, right? I've only been at it for like 7 or 8 years
Either way, it keeps things pretty stable. Even if I saw a .2 difference after a week, i still wouldn't make a correction to my dosing. That could just be testing error/variance.
I totally agree with your previous post though, and is what I was agreeing with earlier... that the benefit to this mostly seems to be to catch something that is wrong, ie. clogged dosing line or something like that. And not having to manually test how ever often you feel is necessary.