Swisha - you might want to take at this thread, Another pH Question. It has some real good info about this same topic.

If you buy the RO water from a machine, take a look at the little led display, before you deposit any money, and it should say when the machine was last serviced. (Around here, the machines are serviced every 3 - 7 days). If you are towards the end of the use cycle, i.e. the next service is just about due, the water won't be as clean as if the machine was just serviced. I usually get 2-8ppm from a clean machine; 40-90ppm from a dirty one.

And, like LocNar said, if you start using filtered water, get some Cal-mag+. But you don't really want to start using it at full recommended dosage. Try 2 tsp/gal to start with and see how your plants like it.

Good Luck!!!

PC :thumbsup:
PharmaCan Reviewed by PharmaCan on . GH Hardwater looking for some info. wonder if someone could point me in the right direction. seems as tho my water is crap, ha. from the tap i usually hit a ph of 8.5 and a ppm of 340. not good. not my first time experiment, so have a little background on growing and lately hydroponics. at first i wasn't using a digital ph meter or tds meter, so went out and purchased some mid grade meters to get me started. and noticed my hardwater problem. throughout my clone/veg/2weeks into flower stages i Rating: 5