no offense...but those plants in the backgroud are droppy and show signs of deficiency in just about every single plant.....a master grower, you are not...
the guy who is running 600ppms is running a hand made, high quality nutrient.....the guy running 1200 ppms is running store bought nutes that dont have the same quality nutrients... therefore the 1200ppm guy has twice the ammount of nutes in his lineup, yet they both achive the same results
showing me 20 ballasts with a bunch of nute deficient plants and asking about where you should start your PPMs at and where you should climb too would suggest you have alot of money, but not a huge understanding of how this all works...
my boy has an investor who wants to spend $100,000 to start a garden....doesnt mean he knows how to grow dank....
honestly, you have 20k and dont understand EC/TDS/PPMs....this might not be your first rodeo, but that doesnt mean youre placing 1st either boss....