I logged onto windowfarms today and this was the post at the top.
After testing two of the taps in my residence, the pH of the water here is 7.
Plants need water that is slightly acidic for best nutrient absorbtion. This will help to have healthy plants in your windowfarm.
http://our.windowfarms.org/2012/02/21/open-source-science-whats-the-ph-of-your-tap-water/
