I know....i think he said something about having the litmus paper you use for pools. Maybe it just happens to pH for him. What pisses me off though is i don't even know what to call it. Don't wanna call it DWC or even SWC cuz he has this shitty little 2 gallon per hour air pump that spews out about 3 bubbles per second. But looking at the plants, other than them being a little lanky due to shitty use of a 400mh...they're healthy as shit.