New ppm pen question

[Pankace]

Just got my Bluelab pens. The conductivity pen measures EC, ppm (x500), and ppm (x700). If I'm concerned with measuring with ppm instead of EC, then which setting should I be measuring with - the 500 or 700?

[Pankace]

From what I understand from the user manual, the ppm 500 is TDS, which is the standard for most cannabis growers. Is this correct?

[SiriusFourside]

That's correct! When cannabis growers use a TDS meter, they're typically measuring ppm (parts per million).

[Royal Nugs]

TDS means Total Dissolved Solids which is similar to EC (Electrical Conductivity). Both are used to determine the concentration of your nutrient solution. Some meters use 700 conversion, most use 500 from my experience. Don't forget to measure your water ppm and subtract it from your solution.

[Pankace]

I'll be using RO water, so hopefully subtracting my ppm from my solution won't be an issue. I will be logging various forms of data daily.

[Royal Nugs]

I think ro may need cal mag supplemented if I'm not mistaken.

[Pankace]

Sweet. Got it covered.