Sounds to me like you're just over waterng! What makes you think that you need to water twice a day? How much water do you add? how much run-off do you get? Does the pot feel very light weight before watering?
If you're only adding a quart or so at a time - you are definately over watering. You should be letting them dry out so they need around a gallon at a time - with only a quart or so of run-off.