Need help understanding PPM meter

[Letsgetit60]

All advice is great advice! Thank you very much for input. I always learn something when speaking with other’s.

[Myfriendis410]

@peachfuzz is my go to for hydro and CO2.

[Letsgetit60]

Thanks for the info.

[Gl1tch]

Thanks for the clarification. I was a little unclear as to why ppm uses 2 scales. I get it now 1S= 500ppm Sodium Chloride or 700ppm Potassium Chloride.