Interesting... I would be into it if it monitored all the critical things that renters for regularly like alk, calcium, mag, phos...from the eBay listing JT just does ph, temp, and some lighting monitors...one add said something about monitoring additional items but no specifics. I'm probably reaching, but it looks to me like they get you in by sellin the base unit at an affordable price but then the real important monitors are going to be extremely expensive...I'm very curious though