Not sure what's causing it nor is the swing that big (back and forth between 6.4-7.5) but it's still bugging me as I've been dosing 2part and just can't get a steady reading.
As of today: Alk=6.5~Ca=440 and Mag=1450. I don't know the reason for the high Mag as I've only dosed once for it at 20ml and that was maybe 2 weeks ago.
My house if pretty closed up and my sis smokes. Would adding an air stone of some sort help?