I don't think anything in the water is harmful. Its not like they are going to put anything in the water that would kill a plant but remain safe for me and my dogs. My water is about 300 PPM from the tap, but I can't justify spending $15 a week just on water and $25 every two on CalMag+, not to mention hauling all that water twice a week. Is it not possible to grow chronic buds without R/O water, or is this just a suggestion? Because I really don't wanna get R/O water. :jointsmile: