pH Regulator / dispenser

[goalie]

I've seen on the internet this device for hydro systems that regulates the pH by dispensing up or down solution so that the pH in the res stays whatever the machine is set to.

Does anyone know who makes it and the actual name of it. I've tried a few stores in town here but they look at me like I just go back from the Future.

[Greenjag]

Check any decent hydro shop on the web and odds are they'll have one of these. They're not that pricey anymore at the lower end. Nutrient controllers exist too but I think I'd rather stay in control of that aspect myself.

Hint: if you can afford it then go for a unit with a peristaltic pump (no contact between liquid and pump, like they use in hospitals) as this will prevent failure of the solenoid valves normally used for dispensing acid/alkali.