Ever seen a tank go pop or one that has? Not a pretty site and i wouldnt want to be around when it goes. Kinda turns you off asking for big fills. I dont know about the rest of the world but our tanks in Oz have to have burst disks and they are a life saver. When they go they scare the sh*t out of everyone around and spray water out of the tub all over the place but most of the time no ones lost a limb or life. I have seen the results of an overfilled tank that was left in a shop that got hit by the afternoon sun. Burst disk blew and the tank went through the glass doors it was next to. No one got hurt and it caused a bit of damage but still way less than the tank going off.

Matt