yeah man you really have to go buy ph/ppm meters. these numbers are absolutely crucial when doing hydro. if your ph is out of the ideal range (5.5-6.5), your plants will not be able to process nutrients properly, and they'll starve. you need to read the ppm's to make sure you're not frying your plants with nutes. seriously if you get through this grow with a successful little harvest, it would be very lucky....not trying to be negative, just realistic. go out and buy that shit.