No problem! I'll be sure to update you once I get it.Thanks for the info.. All I am concerned about is the 12V version having enough head pressure to feed the return side of the pipe. I know the 120V will work with no issues but dropping the cash for that is a little hard to do right now.
As far as the 12v one, I'm thinking you shouldn't worry much. While you may have pressure in your return lines, it's all headed down stream. If you place your injector in the right place (facing downstream), you aren't going to have water trying to sneak back up into your injector. Instead, the water pressure should carry whatever drip your peristaltic pump is putting out.
Honestly though, after looking at the specs, one thing worries me: the <80% humidity rating. Since this thing is going to need some kind of weather proofing box, you'll probably also have to provide some ventilation that moves air well to keep humidity from building up in the box. I'm not sure about where you live, but we get up above 80% humidity pretty often in the summer even without rain. I'm guessing you do too in SC, but maybe not. I'm afraid you could end up going through so much trouble/building weatherproofing that you get close to the $230ish dollars it cost me for the Stenner pump.
Not to dissuade you. I may be wrong about weatherpoofing costs, or the sensitivity of the thing to humidity.