I recently moved from dosing to kalk and love it. I think you mentioned an ATO. You may want to check into adding a stirrer onto the ATO. I got an Avast k1 stirrer. I hooked the stirrer in line with my Tunze ATO. The ATO pumps the RO into the stirrer and the stirrer adds the clear kalk solution from the top into the sump. I have 2 backups in case the Tunze fails. The PH controller monitors tank PH and will shut down the Tunze pump in a runaway situation. If that fails I only keep 2 gallons of RO in the top off container. I have a 180 DT, so even with 2 gallons of kalk dump in at once the ph should still not spike to high before action could be taken.