There should be a way to swap out water in a container for the water on a tile. The current method makes water quality testing an unnecessarily tedious activity that I'd personally solve with scripting to empty containers. Either changing how water containers interract with water tiles (completely filling up with the new water and "dumping" the old) or a tool to do this would be very much appreciated in the early stages of the world.
Lucky: haven is so quirky Lucky: can be so ugly, can be so heartwarming Sevenless: it is life