Correction:
Tap Water reads 7.6
I poured out a gallon and started adding pH down. It drops 0.2 for every 2 drops I put in.

So if I'm starting with 7.6 plain water and 7.0 with full strength nutes.
How much pH down should I add to my tap water? 8 drops/gal to bring it to 6.8? more?
What about nuted water?

I guess I'm asking what the ideal soil grow pH in and out should be.