You as well as me have a real high ph i your tap water, where is your ph i water coming out of the soil? I really dont like that i have this big gap beetwen water in and out. Some says it dosent matter and some says it does matter. And i dont have a clue...hehe
The pH of your water and runoff may or may not matter in organic grows depending on your medium, what sort of nutrients you are using, and your water. The best way to tell whether it is an issue is to observe your plants. Given that you are pHing your water down and the plants look good, the higher pH of your runoff water probably isn't an issue. My advice would be not to worry about the pH of your runoff.
Plants do have some ability to regulate the pH in the root zone so may not even need to adjust your water going in, but the only way to gauge whether you need to adjust down or not is to try not doing it. Everyone's water, medium, and fertilizers are different so I don't think a one-size approach fits all, but personally I have not found any benefit to pH adjustments in my own grows using high mineral content well water with a pH of 7.8.
Pine