This is a damn good thread, I'm growing in Roots Organic soil at the moment and have been experiencing all the same problems as some of the other users.
I didn't know what "organic" meant at the time of purchasing the RO soil, I thought it was like buying an organic apple from the grocery store. After doing alot of reading, googling, and what not... I came upon this thread.
I'm using the following nutrients with my feedings:
Organic Nuterients: Aurora: Budda Grow, Budda Bloom, Trinity and a Vermi T compost Tea
Non organic nutes: Bud Candy, Gen Org CalMG
With that being said, after adding 5 ml of each into 1 gallon, my mix was at 5.0 PH and ~800-900 ppm. At this point, I didn't understand how micro organisms and all of that worked yet, and decided to use PH UP to bring the PH to 6.5. I use tap water that has been left out for a few days.
In between feedings, I water with the same tap water that has been sitting out, the problem here becomes the PH rises in tap water that has been sitting out. My tap fresh off the faucet clocks in at ~7.1-7.2 and jumps to 7.8-8 after a few days of aerating. This being my first grow, I've been PHing the water DOWN to 6.5 for my regular waterings and PHing the water UP to 6.5 for nutrient feedings. I'm betting this is the cause of my eagle claws and the lower fan leaves yellowing.
I'm at day 35 with my autoflowers, anyone know if I should just leave well enough alone and stop using PH up or down?
With my next grow, I will not using PH up or down with my roots organic soil, I will just amend it with dolomite lime and let the microbes do there thing.