Watering with RO/DI water

Okay I have a couple years experience with plants, about 4 weeks with herb and so far i have one female whos 4 days into flowering looking like a champ. (just a little backround) at the first 2 weeks i used regular tap water to feed the plants. the soil was drying out within a day or less. i switched to my RO/DI (reverse osmosis) water and the soil is staying moist longer and stays fluffy (rather than that crispy dry flake soil). i just wanted to let everyone know that there is another bonus to making your own purified water. im sure if ro/di water was tested on herb side by side with tap water there would be a definitive line between them. currently i use my ro/di water for my fish tank, plants, and drinking water (tastes better than bottled water!) got mine from http://www.drsfostersmith.com/product/NavResults.cfm?N=2004+113773
best $100 ever spent
they last over 1,000's of gallons