Word, you're a lab rat too?
Hard water is going to cause troubles, so yeah you are better off with distilled for now, and 5gal isn't TOO bad. If you run a dehumidifier, those produce 'distilled' water too FYI! Just make sure it's not loaded with metals- check the EC on it.
I don't know nute schedules off hand, sorry, but definitely go easy on supplements until you have your base system running perfect. That is my advice for the day! :jointsmile: Have one for me; I'm crunching GC data this morning and need my brain less cloudy, although TBH I think a bit of smoke would do me good! lol