How can I empty the hot tub?

The hot tub is equipped with a drain hole.
If necessary you can connect a drain with a valve and install a garden hose to re-use the water etc.
It is not necessary to change the water after every usage.
The water should be changed as needed.
For maintenance you should use biodegradable water care products. This will prevent the formation of algae and fungi.
In winter it is important to ensure that the water does not freeze in the barrel, because the frozen water can damage the barrel as it expands in volume.