Operative word should, never underestimate the unpreparedness of a small business owner... Especially one who operates in woo woo spaces.

Cleaning such a space is simply the cost of doing business. It's absurd to claim they'd have to just chunk the whole tank when a gallon of bleach and some water would nuke it clean.

You're right they have insurance, but I wouldn't make a claim and raise my rates over a nothingburger.