No distilled water! It's a complicated issue - can't remember how but it can remove nutrients. Tap water is fine - especially if you drink it too! Just get a bottle brush maybe
To clean the bottle out.
Newtie loves baby spinach. I give it a couple of times a week. I get it bags from the supermarket already washed - trouble is a bag only has about 2 or 3 days date on it and bagged stuff needs to be kept to use-by dates.