New Grower PPM QUESTION?????

[Bud Wiser]

Do you include your tap water ppm in the total ppm or do you subtract it from the total ppm??? I do not know what my tap water consists of.......I just know its apporx. 160ppm

 

[Bayes]

For me, the absolute ppm value is not as important as the relative ppm change, i.e., ppm value of feeding vs ppm of runoff and also ppm of runoff this feeding vs ppm of runoff last feeding.