I'm from europe, I have been using GHE Flora Duo for about 1½ years, It's the best stuff I have come across for hydro/aero grows. I am going to give it a go in coco in about two weeks, It's very easy to use and I never use additives other than some cal/mag since I am using RO water. When you find the sweet spot (ppm, ph & watertemp) for your specific plant, with this stuff, you'll get 1 gr/watt each time, no co2 added to the room, just venting air...