i got this quote from the green Queen herself

Quote Originally Posted by stinkyattic
Indoors, you need to use water that has minerals in it.
Rain water has NO calcium carbonate in it whatsoever, and your plants NEED that to grow. Also, rain picks up contamination in the atmosphere, such as Nitrogen and Sulfur from smog and other fossil fuel combustion byproducts. When that interacts with moisture in the atmosphere, it goes into solution as nitric and sulfuric acid- not good! It will quickly use up the buffering capacity of your soil, which is guess what, calcium carbonate added at the packaging plant, and the pH will suddenly drop.
So if you use rain water, you must add CalMag Plus to it, and then adjust the pH before each watering.
Tap water is almost always better.
maybe why i had bad experience was the absence of calcium but my plants drooped too fast for that to be a problem. it prolly was just the region i was in where i collected the water. i did adjust ph but didnt add any calmag but my plant wouldnt respond that quickly to just an absence of cal.
cigarettes42 Reviewed by cigarettes42 on . Water into weed Today I've collected about two gallons of rain water for my plants will it do themany good. Whats the best kind if water to use when watering your plants? I've heard that rain water and distilled water work well, but what about tap water, purified water or even spring water(bottled) how do they work out when watering you plants? Rating: 5