Tri-Meter is the brand. For me it is fool proof, something I need when I get high.

Here is one site that sales it, I got mine a local grow store.
Tri-Meter Continuous Monitor PPM/pH/Temp
fosomker Reviewed by fosomker on . PH/EC Testers. What Do You Use? And do you love them, hate them or could take or leave them? Which ones do you guys think are the best and the worst? Fast or slow? Easy or hard to read? How about to calibrate and store? ALL meters...ph, ec and/or tds any info would be great. :thumbsup: Thanks. :jointsmile: Rating: 5