Dosing all-for-reef, suddenly alkalinity has dropped and calcium has risen

[marbdo]

Been dosing all for reef for a while now, tank is still new and not a giant amount of corals so only needed 4ml a day.

Been stable for weeks but all of a sudden alkalinity has dropped from 9-8.3 and calcium has risen from 430 to 460. Why has this happened?

On a side note, I recently purposely raised by magnesium from 1250 to 1400, could that be the cause? The timing isn’t exactly correlating but still

 

[Randy Holmes-Farley Verified Community Expert]

My suggestion is to not try to chase down every small change, which may be real or just test error.

I’d up the dose to stabilize alk where you want it unless calcium gets much higher (say, above 550 ppm).