Hey DD, I must say I am not an expert of ppm measurements but as far as I understood:
Seedling or a cutting approximately start with 100-120 and slowly slowly, during the mid veg phase it increases, from 300 to 500/600.
Afterwards, when reaching the end of veg growth, the ppm can go up to 850 ppm.
Last but not least, flowering stage, can go up to 1000-1300.
Hope I have been of some help
All the best,
Originally Posted by DoDad
I tested my tap at 187 ppm. What should my max PPM be for rooted cannabis?