Hi there, have just bought a new large tank which came with an eheim professional 2 external filter. The problem i have with it is if you turn it off, you have to shut off the hoses otherwise it keeps drawing water from the tank and overflows. The worry is if theres a powercut while im not about to shut off the hose then it will flood my living room and eventually empty the tank... Is there something im missing? Or faulty seams around the filter lid? Thanks folks