how's the saying go 'hope for the best, plan for the worst'? hehe
i just want to be prepared. and no, no negligence here, but who knows, i've seen plenty of people have power outages, cleaned and used some chemical, kids spilled something in the tank, something dies and it's not seen right away, something emits a toxin...
you can't plan for EVERY situation, but to have a better idea than 'i hope it doesn't' would be preferable...