Snow water ??

Hi, Its snowing where I am, I have a waterbutt to collect the usual rain water, I presume snow water is the same, can i use it once it melts and drips into my tank or should i flush out my tank and allow it to build up with rain water instead?
I believe all it is is rain freezing in the air, is this correct?

If growing hydro use tap water, RO or distilled.......not rain or snow. And if you do use RO or distilled water, don't forget your CalMag. ;)

Im soil based, is Calmag the same as a ph testing kit?

Weedhound's right, there are unwanted contaminates in melted snow just the same as in rain water. The closer you are to major industrial areas, the worse the pollutants become.

And CalMag supplements the Calcium, Magnesium, Iron, and trace elements that aren't present in distilled and RO water. Normally, when using tap water, these elements are present and in enough quantities to prevent deficiencies... but in distilled/RO water, they've been removed.

those unwanted contaminates usually amount to acid (you've probably heard the term "acid rain"), so if you plan on using rain/snow water make sure that the pH is okay before you use it. depending on the pH of your local tap water, and the proximity of industrial areas, this extra bit of acidity may be enough to raise the pH to dangerous levels.

Acid rain - Wikipedia, the free encyclopedia

Many thanks folks, cheers!