Water when the first couple of inches are COMPLETELY DRY. Watering every other day with CFL's is way too much, I water about every 3 days with my HPS and I only have to water that often because of the intensity of the light and the heat it puts out.
Water from the top until you get a 20% runoff. Wait about five minutes for all the excess water to collect at the bottom, then chuck the excess. DO NOT USE THE EXCESS WATER AGAIN!