I just did the joyreef project for a diy doser.
Totally worth it, but my initial investment since I started with no solder iron or anything was about $130
But because the chips are sold in packs on
amazon where I got them, I have enough stuff to build 6 more pumps with up to 6 heads, pumps permitting.
I planned to do 6 initially but stayed with 4 so i have 2 dosing pumps left over at the moment.
Highly recommend, now I can fix anything on it no problem, and I didn't even know how to solder, i just jumped in.
I would recomend taking his recommendation on using the pre built circuit where you have to chop the motor off it as it seemed slightly easier than buying the IC and making the circuit yourself. But it was also easy to just make the circuit.
If you do take this route, i will definitely help you if you need tips, it was a super fun project and totally fullfilling. Finally having a dosing pump this last week has made a huge difference in figuring out my exact alk and calc consumption and properly employing the balling method. And now I dont have to worry about the reviews of issues from the sub $200 dosers.
If you buy smart, you can honestly make a 4 head as cheap as $60, i just took the route thay got me the fastest shipping. (Unles you also need to buy tools which may run you an extra $35-90 depending on how few tools you have.
Edit: I also went with the cheapest recomended pump heads ($6), and appears to be acurate to .2ml and does not have siphon issues. Sounds like a windup toy when it runs, but with it being in the living room, somehow the wife and kids don't notice it going off so it must still be considered on the quiet end.
