Hey everyone, I was looking at ppm and hopefully someday it will make more sense to me. I have a meter and it says it’s calibrated by the mfg so I don’t need to (?). If I use it in some purified water I get about 3 ppm so maybe it’s OK, I don’t really know. But the question I have is comparing what a TDS calculator says compared to what the TDS meter says the ppm is.
If I make a mix using a 32-10-10 plant food this calculator I found online (photo below) says the total ppm will be 589 (plus whatever your water is (so 729 ppm) but using the meter I get a ppm of 365 at 77F in water that started at 140 ppm with a pH of 6.22. I’m in week 4 of vegging and have just been using half of what the mfg. instructions say to use to mix in a gallon of water. The plants look good and healthy but I am probably a bit past the point where I needed to up the ppm. I’m just not sure if I should go by the calculator or what the meter says.
Any thoughts or advice on this would be appreciated. It’s a Zoto TDS meter so it’s not for scientific research The meter is reading 1/2 of what the actual is if that gives any clues or may be just coincidence.
Shot of online calculator
HK47 Plant 2 days ago. Its on Day 27.