N non1994 Well-Known Member Jan 4, 2012 #1 how do you know if your ppm is reading correctly. i got mine from a friend and i want to make sure it is working correctly..
how do you know if your ppm is reading correctly. i got mine from a friend and i want to make sure it is working correctly..
littlegiant Well-Known Member Jan 4, 2012 #2 I have a $45.00 cheapo and you can calibrate it with solution you purchase at your grow store.
T tibberous Well-Known Member Jan 4, 2012 #3 Buy a second one, see if the reading on your current one matches. If it doesn't, buy a 3rd one - if 2 match, then you know which one is wrong. If all 3 readings are different, buy 2 more, and see if any 3 match.
Buy a second one, see if the reading on your current one matches. If it doesn't, buy a 3rd one - if 2 match, then you know which one is wrong. If all 3 readings are different, buy 2 more, and see if any 3 match.
