I never worried until my blasted peacocks managed to unearth a thin layer of substrate and a rock pointed right into the base of the tank--44 pentagon. Just a small place, but displaced about 15 gallons on my carpet (trailer, too). Worst part was I lost my beautiful Taiwan Reefs.
I wasn't untill I read this thread!!!! THANKS GUYS! .. Kidding... I don't worry about it ... I keep the big tanks in the basement and have drains in the floors LOL... There is always someone home here so I don't worry about losing the fish to much either since everyone knows what to do in case of emergency
I was terrified in the begining knowing that the builder of my tank had never done it before since it was me. I would wake up to any noise in the night and check on it. After about 6 months I got over it. You pays your money and takes you chances.
Guinness
I was in bed wondering what people felt like when their tanks broke and then all the sudden my 90gal goes BOOM then PSHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
Cracked at the bottom, thank god it wasn't my main tank and only had a goldfish in there or I would've gone
P.S. don't think about tanks breaking, cause they do