You can NOT use bottled waters. Period, unless you want to kill your plants. Distilled or rainwater only. Or reverse osmosis water but that seems expensive to me. No filters either. They don't remove all the bad stuff for CPs.

R/O water is much cheaper than buying by the gallon!!!
The up front costs are what can be prohibitive to most.
You need the unit maybe around a couple of hundred and you need something to collect the water in, maybe another eighty bucks. If you use alot of distilled water than check out investing in an r/o unit.

You can also collect rain water and as I do - a local creek - but you have to know your creek!

I use rainwater unless I'm out (rare)then I use distilled. I use a 32 gal. plastic garbage can and a few 5 gal. buckets to catch rainwater off my back porch roof.

NO to the purified drinking water, particularly since it has added sodium (salt).

If you are in your own home, rainwater is easy to collect and costs nothing. Just reroute your eavestrough runoff into a storage container. In winter, collect and melt snow if you are in a snowy climate.
-Don