I wish I could help you here I refuse to soil grow lucky I have a 5 yr old lucky that has been in distilled water sence day one. I scrub it's pot at least four times a year and do a water change needed or not once a month.

I can only guess it would depend on what kind of pot it is ( IE plastic, ceramic, clay)If me I would of picked a clay pot a *well drained medium of some type and still use distilled H2O (*I have no idea on what kind of medium materials you'd need for lucky)

Wall Mart water concerns: Is that filterd or purified or spring h20 any flavorings with in it ect ........?

Tap water : usually contains salts chlorine and other chemical junkie stuff it would be a definate big no no from me on tap not even for my tea either

I play alot with pH, Distilled h20 is perfect water for any kind of plant at 6.0 pH. I don't plan on changing to soil on my 5 yr old lucky anytime in the future it will always be in distilled water and it's original ceramic pot.