The problem is in the res. you need to keep that constant becouse as the water and nutriets get used the ph rises its prettly simple you can use this controler but i recommind a more percision dossing pump than that one you have to dilute or you could use to much to fast. If you have the cash use one of these and if you really do buy the all in one its as simple as plugging it in, and if you have know how build it super easy. This is just one good place to find these pumps and they make their own systems.
http://www.automatedaquariums.com/h_sys.htm

they also sell just the pump which can be used with the milwake for i think 75
hazeywonder Reviewed by hazeywonder on . Anyone built the PH doser in the faqs? (other than Gen) I'm seriously considering building the DIY PH doser in the FAQs. http://boards.cannabis.com/showthread.php?t=58098 I was wondering if anyone else other than Gen has tried one, and if so, what do you think about it? Any thoughts, ideas or additional suggestions. I want to be able to mix up my nutes in the sink but not worry about PH at that point, then dump them in the reseviour and let the doser take over. Of course I would turn off my pump until PH is stablized. Is this the general idea? Rating: 5