Randy Holmes-Farley
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My Tank Thread
I have the same issue. I am adding approximately 10mL AFR daily to a 47g to keep the Cal and Mg at 410 and 1340, respectively. Alk is now down at 6.1. I was previously supplementing with 10 mL daily of Brightwell alkalin8.3 to keep alk separately at 8.5. Alkalin8.3 apparently is a bicarbonate solution but has some other ions like borate that I didn’t want to keep adding. Once I stopped, alk dropped about 0.1 units daily until it stabilized at 6.1. I’m now considering slowly raising alk again to 8.5 using a sodium hydroxide solution dosed at night to also flatten out the pH swing.
Dose more. Always dose enough AFR to maintain alk, IMO. You will hardly even detect the calcium change and definitely not any magnesium change.