Reading in another thread about success with Daphne cuttings reminds me a misting unit is something I have always wanted, but it is (was, before current regulations) easier to organise electricity in the greenhouse than automatic controlled mains water supplies. Most years I have sufficient rain water for all my greenhouse watering by hand, and a new setup I am organising will even have it on tap, due to land gradient giving enough pressure/head.
What I am leading up to is how important is the water quality for misting assisted rooting to work satisfactorily. Mains water is clear and chlorinated, and more or less sterile generally (yes I know about brown peaty water in parts of Scotland), so is stored untreated rain water useless for misting because of potential "bugs", assuming I can filter and pressurise it? I thought about using one of these artificial fog units at one time but never tried more or less for the same reasons about the water quality.