Never mix and dose at the same time! Youll be delivering any impurities that might be available in the solution... You should mix right before lights off when the Ph is at its highest and dose during the night to stabilize Ph. Mix for 15 or so minutes and let settle for a minimum of two hours. When yor Ph begins to drop during the night, thats when its time to recharge your reactor. I can help you with kalk dosing issues, Im just not familiar woth the Litermeter system.