Thank you for the great and full answer, you could well be right. Unfortunately, I do not have any malted barley or a coffee grinder.
I think there is some malted barley in pre-packaged form from a nutrient company, so I'll take a look into that.
Don't you think PH is the issue?
Sorry. I had some problems with my DSL connection. Internet was down for awhile...
pH an issue? Seems so. For "organic" products, a low pH seems odd though.
Can you snap some shots of the ingredients/fert' label for the products you're using?

I was using straight RO for awhile but ran into similar issues.. MOG recommended adding just a little cal-mag 50-60 ppm ph 6.4 then send it.... Cause pure RO and distilled will go acidic rather quickly