Obviously to a certain extent, yes. But I wouldn't worry about it. My water is full of minerals, and it doesn't seem to bother the plants - grown in coco. Minerals found in water are usually calcium and magnesium salts. Just give less CalMag!
i use hard water in my hydro setup i know its not optimum (r/o filters are expensive maybe soon lol) as long as you check your ph regularly it doesnt seem to give me any problems just have something to adjust your ph on hand and you should be set my setup works fine but still i would like to use r/o water if given the choice
actually hard water can be a benefit if it is ballanced right and has the right minerals in it. The problem is that it is impossible to check without expensive test kits or taking it to someone who can test it. I have a "small boy" filter that does a real good job of removing a lot of the bad stuff and it wasn't real expensive. It's not RO so there's no waste water. The GH for hard water should take care of any probs that yu may have with that tho. grow mojo
ya i just picked up a small filter too that goes on my tap and honestly i dont have any problems i know the potential is there from not using r/o water but like i said i run it in my ebb and flow table with no problems