End of Flower Week 3 / Wk6 from Seed: 1st runoff measurements taken @ 2100 - 5400ppms so all were flushed multiple times with pure Brita filtered water [5.8pH, 67ppm, 70F]. Final runoffs average around 1700ppms. Switched to 12/12 light schedule last night. The plants are frosting up. They are all due to harvest in 2-3 weeks.
Yes week 5 is EC and PH stacking caused buildup in your medium. Since I want to automate watering I'm learning about this and discovering how watering frequency of a somewhat constant content and duration is how you control a stable PH and gradually rising EC in your grow.
The beginning of this recent video shows a good example of steering feeding just keep in mind you have to analyze your own grow medium.
www.youtube.com/watch
Noticed after vigorous growth in week3 seems there was a stunting between week 3 and 4 possibly from too much dry-back and not enough microbial activity.