Quick question.. something I've noticed is that when I'm ph balancing pure RO water, the PH meter is much more sensitive than when PH balancing soup/nutes. I'm finding that when the water has nothing in it, for example, I can wiggle or stir the PH meter inside the RO water and it will drop the PH a few tenths of a point, but if you let the PH meter sit still for 10-15 minutes it will rise up. This is a difference of about .6 for me with the current RO water I've been getting (6.3 to 6.9) so I'm curious... should I be dropping this water until it sits at 6.3 with the PH meter sitting still for 15+ minutes? or am I doing the correct thing by using this water that gets down to 6.3 when I stir the water with the PH meter? Thanks,
Pure RO water with a ppm of zero does indeed take substantially less pH adjustment to change. This is because when you add nutrients that have their own pH and add to the ppm then the solution starts to become buffered so that it resists changes in pH a little more. It gets really noticeable when you are making 200 gallon mixes and it takes tons of pH adjusting to get it to move where you want it to.
I'm just doing 1 gallon a day at the moment for my 2 girls. My RO water is at 009 on the PPM meter.. any idea on if I should just leave it be where it drops to 6.3 when stirring with the PH meter and will rise to 6.9 if I leave it at rest for 30? Or should I be ph'ing the water down to be 6.3 when it's at rest for 30 min?