The best water I ever used for my houseplants came from our aquarium... town water is chemically treated, so I allow it to sit for a day or so before using on my plants..laundry water might be alright for a garden if no bleach is added but its still got chemicals in it from the detergent..I would use rain water if it was not collected coming directly off a roof that had shingles on it, etc.. Spring water might have alot of lime in it and leave residue on the soil but its still a better source than treated water... but you use what is available.. you might try finding a homesteading forum for some in-depth answers..they are well acquainted with water problems.

Learn to refine your searches and you will come up with plenty of information. Use the right search engine, too.

Here is a link that might be useful: try this link

Bottled spring waters are all different. Mountain Valley Water used to advertise that their water could be used for germination in lab experiments. When I used to be able to buy it, it grew way superior bean sprouts than any other water, bottled or not with almost 100 percent sprouting. However, it is no longer sold around my area

Because I saw such a difference in growing bean sprouts, I suggest that is a very good way to compare waters. Buy a large bag of seeds. Use different waters to soak, and water sprouts. For this, you do not need soil and the difference in sprout size and vigor is very obvious.

Compare the following:

1. water

2. heavy water (deuterium oxide)

3. water with deuterium oxide removed (concentration of deuterium oxide in water is about 0.147 mole percent)