Rain water

So if I were to put a 150 gallon resivour out for the winter and let it fill with rain water would this be good water for my plants or would the ph be off. Iv'e never heard of people using water thats why im asking this question?

yes, you can. check the pH and adjust it if needed. the only (small) problem would be acid rain...but hey, as long as its within the suggested ~6.5 range.

yea you could even melt snow for water and check ph and such

put a screen over it
you dont want a bunch of crap gettin into the water

cannabis should grow fine with rain water just like all other plants do