Yup I'm at one drop per gallon. My PPM for reg water is around 130-140. I got 2 3 watt 2 outlet activeaqua air pump, so one line per 5 gallon bucket.(2 pumps in total) Outputs at 7.8l/Min, pressures >3.768 psi. As for measuring the PH, I understand getting a meter works best for DWC, but I'm...