I'd like my dosing pump to do a fixed dose every 30 minutes, which is easy enough. However, if the pH of the tank is higher than a set amount I don't want it to dose at all.

I'm assuming this is something to do with the Programmable Logic but I don't entirely know what - is it possible to control the doser like this?

(Also posted in pumps which I think was the wrong section of the forum!)