The first knuckle in the soil method is full proof. I only use my h2o reader to confirm what my finger told me. That's when I give what they need. Their needs change all the time. I like to flush no matter what every 3 or 4 times, phed water only. Emerald harvest all the way for nutes, calmag and stalk included(might back off those 2 for a while, I think I see signs of something building up and blocking the girls chi flow), full recommended doses for the rest. I test for ph after everything is added to the water. It takes me about 3 hours to water all my ladies, they like it slow...I test the run off ph also and the soil usually the morning after, the excess sauce is removed with the shop vac. Happy girls!