Test your tap water if it tastes weird or leaves white crust on your kettle. You might discover your water is a mineral bully—and you can get a filter to fix it.
Test bottled waters for fun. See which ones are actually pure and which are just fancy tap water in a plastic disguise. You might be shocked.
Test your aquarium water if you have fish. They’re very picky about dissolved solids. Give them bad water, and they’ll give you the fishy equivalent of a stink eye.
