For how long can I leave the wooden hot tub empty?

If the wooden hot tub stays empty for a longer time, it can dry and start to leak. To avoid leaking even if the hot tub has stayed empty for quite some time, please follow the tips below:
What should I do in case the barrel leaks? If the barrel leaks, the bottom should swell tight first. Do not fill up the barrel with water completely, the water leaks out anyway. At this time it is not recommended to tighten bands of the barrel.
The timber must be able to absorb enough water and the barrel swells tight.
* Fill in only about 10 cm of water and leave the hot tub to stand overnight. The bottom swells tight.
* After fill the hot tub with water continue filling in 10 cm steps. The wood absorbs the water and the hot tub swells tight.