I recently read Mr. Grow It's book that I bought on Amazon, and just got done setting up my first grow tent. I plan on doing autos for my first grow in a 4x4 grow tent. I plan on using the paper towel method and then planting in to a 5-gallon fabric pot of FFOF soil. I wasn't sure when I would start getting a reliable PPM reading according to the cheat sheets in the book. It does mention I do not need to feed for the first 30-40 days since the soil contains all nutrients needed but I wasn't sure when I could actually start measuring the PPM accurately.
So, my question is when do I start using the cheat sheet for measuring PPM using FFOF soil for an auto grow in 5 gallon fabric pots? Thanks!