parts per million

Hi, general question for those experts out there. My schedule says add growth nutes to your solution at a measure of 1.5 EC. The EC of my water prior to nutes is 0.4. Does this mean: 1) Add your nutes till your measure is 1.5; or 2) Add your nutes until your measure is 1.9 (a...

Hello everyone, Just wanted to ask if anyone here uses the Bluelab truncheon and thoughts on it. Im looking into replacing my current pen and have started looking at Bluelab's pens and the truncheon specifically. Looking at the trunchion over the pen currently due to a 5 year warrantee vs...