Great Demoral, very true.

I find that even the local weather can effect my tap water and RO water, specifically the PH. Also my tap water has very high iron content. But, I must monitor my PH, especially during the rainy season as it fluctuates greatly.

ALSO RO water is unstable and will try to stabilize it's PH over a few days time. I always let it sit for 24 hours to stabilize before I check the PH.

ALSO RO takes out Cal/Mag and you need to replace it. Filtered does not.

I have a bud on the same water, and filtered works just fine for him, and I gave him all his starts, so same plants to some extent.

The point? All the water supplies are different and you need to tailor to your water supply. Best of luck.