I am growing in 1/3 Ocean Farm, 1/3 peralite, and 1/3 coco using 2-Part Emerald Harvest nutrients with reverse osmosis water (my tap water is extremely 'hard' with chlorine and chloromine's). I water & feed drain to waste. I did a feeding in week 3 of flowering (day 55 from seed) and had a drain to waste run off pH of 6.5 which was within 0.5 pH from my 6.0 pH feeding solution. Okay, but it was near the edge of my limits so when I watered mid-week when the grow media was very dry using my usual Cal-Mag and RO water solution but pH adjusted down this time to 5.8. However, to my surprise the run off pH was at 7.0! So I checked my pH meter and the calibration is right on. It just doesn't make sense to me unless the plants themselves are wildly changing the pH of the Grow media as they mature more in the flowering stage. Could that be true? I am trying to figure out why the run off came out so high so I can properly adjust my next watering or feeding pH. Any ideas?