Oh man I've written out the explanation for that like 5 times in the last week... okay here goes. Drinking water (bottled) has minerals added for flavor, and higher sodium than you want. Tap water would be more likely to contain calcium and magnesium and lower sodium. Plants need Ca and Mg.
If the tray is attached, remove it from the pot, otherwise, you're good to go on that.
Your pH sounds decent; using tap water will help keep it that way.