Reasons I ALWAYS Use R/O Water

• Cannabis is not a common fruit or vegetable, it is an accumulator plant. It enjoys additional pathways than the "Passive Ionic Uptake" pathway all plants use
• It draws excessive and un-necessary elements through these additional pathways
• It binds excess and un-needed elements directly to new growth tissue where it will not flush/fade out

Local tap water varies considerably

• Seasonally
• Geographically
• pH buffering
• Unnecessary elements for plant growth

I Grow Strictly Hydroponic

• Cannabis is an accumulator and precisely controlling available elements grows superior quality cannabis. (Yes, 99% of hydro cannabis is garbage because the growers don't realize this)
• Using r/o means rock-solid, predictable pH behavior
• Moving to a new water supply doesn't require learning hydro again

You would swear my cannabis is grown organically. You'd be wrong though. The smoke is so smooth and soft, you'd swear you haven't taken a toke. The amount of exhale is always a surprise. The flavor and aroma are so strong you're chomping at the smoke (even on the last exhale) to prolong the experience. ;) Yeah, that's the kind of cannabis I'm talking about. :D

Most fruits and vegetables? Tap water all the way, as long as it's reasonably clean.