I have a nano cube tank in my office and today after a week, I got back to work and found my Bristlenose pleco dried out on the carpet. I've had her for almost a year and she was always a happy/active pleco around the tank. The tank has a lid with a tiny hole for feeding the fish. Why do fish do this and why plecos? I've had jumpers before but never a pleco. The tank is well-established with filtration and lots of healthy plants, I haven't tested the PH or the ammonia level, but I don't think they are high. Beside a little algae build up on the glass, the other tank mates (a couple of Guppies and Cherry Barbs) are doing fine.