VERY sweet! Thanks for sharing the info! Can you do a PH doser for dummies maybe when you get that far? Very interested in your DIY doser details please sir. Plants looking all perky also!
I'm doing a combo dosing unit next. 2 part nutes and pH, using the Hanna controllers, wired in to one box, controlling 3 remote pumps. This unit end up costing ~$560 in the end, but compared to AMHydro's doser, Its a bargain. Granted, I don't get pH up AND down, software, logging, etc. but for $1700, I can live with out it. I can also customize and add pumps for $70ea If I wanted to dose additives too.
I will take pix, type up a howto, etc. but its pretty basic.
For a very simple pH doser (like what I currently have), you just need a Milwaukee SMS122, a 5 gallon bucket(or smaller), and a tiny pump. I used 'reptile' pumps available at PetSmart (Repti-200) or something.
You could ALSO use an airpump, airline and a tee to push solution out (similar to the way a WaterFarm works, if you understand that concept) instead of the reptile pump. Not sure on the pressure, head it can generate though.
The controller has a built-in plug outlet for the pump. When it reaches your set point, it activates the outlet and the pump turns on. The pump is such a slow little thing and the pH down solution is VERY dilute (50ml of AN down in 5 gallons) , that it adds a tablespoon or three to the epicenter and kicks off. As it gets closer to the set point, it cycles more and more frequently until it stops dosing completely. Not sure how hard it is on the pump, but they are cheap and I have spares. All told, that cost me ~140$. 120+ for the controller, a few bucks for tubing and a clean bucket and lid, and like 12$ for the pump.
Milwaukee makes the 122-X (Don't remember exact model) that doses pH UP. That will activate the outlet when you go BELOW your set point. My needs require pH down, very rarely up. Make sure you get the one you need.
With the new one I am building, I hope to have a little more control over it and the ability to use more concentrated pH solution 100:1 or something. Cost is slightly more due to the very small pump dose (5.6ml/min), but controller, probe and pump for that is ~$230 and will allow me to wall mount it and get a much smaller container for the solution vs the 5 gallon bucket.