Sounds like good drainage so far.
It's certain that the hydro shop will also stock soil nutes. A word of caution, hydro nutes are designed to mix up at pH 6, while soil nutes if they are good quality should come in around 6.8.
Get your pH tester and a bottle each of pH up and pH down, because with that strange tap water, at some point you WILL have to deal with pH adjustments!

Good soil nutes are pure blend pro and canna terra- these are both made with ingredients that stabilize your soil pH- look for 'humic acid' or 'leonardite' as an ingredient if you have pH issues. There are lots of other choices but in your case, with high pH tap water, I'd DEFINITELY spring for a fert that has some nice organic acids in it, and they really aren't that much more expensive in the long run.