As I turned on the hall light I heard a funny sound coming from my living room. I walked to the top of the staircase and my first thought was holy **** I had alot of water evaporation over the night, then I woke up and realized my 29 gallon tank was about 5 to 7 gallons lower than when I went to bed. I ran down to the basement and grabbed a small tank and a siphon and began draining the tank as quickly as possible. Luckily it was only about a third of the way down and the leaking stopped. I figure I must have comprimised the sealant yesterday when I did a water change. Now I have to set up a differant tank.