Hmmm I got about half that on a smaller pool, a tonne of water being a cubic metre and 10m by 10 m being 33 feet square (the tonne/ton conversion factor would take  the pool size to about 36 feet, so you'd still be looking at less than 7cm unless i made a mistake at three in the morning.

Any idiot can face a crisis - it's day to day living that wears you out.