In this thread post your most idiotic reefing mistake

[mark]

Tank is upstairs, sump/return pump in basement and in the basement ceiling there's a return air grill. When doing a water change I'll siphon out about 20g from the tank leave the siphon going, go downstairs turn on the return pump for a bit to top the tank back up. Rather than heading right back up once, got doing something then noticed water streaming out of the duct into the basement. The hose had come out of the tank, landed on the floor and siphoned water out of the change barrel. Water flowed along the floor, under the baseboard into the joist space then onto the basement.

Was only a few gallons but it sure seemed a lot more when spread over two floors. Lucky return air duct was there though since water didn't pool so no damage. Lesson learned, secure all the hoses and a shop vac can be a reefers best friend.