First i would caution you that controlling your PH that way is likely to cause ALK spikes. A good friend tried to control his PH the same way. He could not undestand why his alk would get crazy high and kill his corals. A lot depends on your ALK consumption. Also PH depends on a variety of things not just ALkalinity. I would set it to dose at at night and stop when PH reaches 8.0. Once your lights come on the PH will raise up more. Then I would keep a close eye on your ALK levels and adjust as needed.
I have mine set to dose a specific amount at night, but shut off if my PH should get above 8.0. I can easily adjust the amount as needed to keep my ALK where I want it.
i have a couple of different brand new and used dosing pumps that would work that I am not using.
I have one and some lightly used
BRS dosers available. I would sell the new one for $60 and the used ones for $45.
I also have a couple new dosers with adjustable dosing rates if I recall correctly I would sell for $50.
