I use to use magi-cal and I ended up decreasing the amount of nutrients I was feeding and the need for the magic-cal went away. I don't use RO water, I have an excellent rock well. I'm working on using molasses in lieu of sugar daddy by bubbling 1tsp/gal of balanced water for 24 hours.....use it as I would sugar daddy, and so far with tomato plants, I see no difference. I'm about to start using it on a few of my girls in hempy buckets and if there is no difference with them, then I'll be a believer. But so far, it has had no negative affect on my tomato plants. hope this helps.