And yes distilled is fairly comparable, not ro but better than tap.for sure.
Hey bro!
Distilled water is usually done via steam distillation. The PPM of distilled water is ZERO. RO is made via ion exchange through a semi-permeable membrane. PPM of RO is usually between 3 and 20.
Either or both of these will work perfectly for foliar sprays. The tap water will probably work as well, as his Total Alkalinity is about 60 if I recall. It just buffers the foliar sprays too much, and they need to be very acidic.
They're designed to be used with RO or Distilled.