Many thanks Jax for your valuable feed-back and suggestions. Yes, the pool is outside. It's a bio swimming pond und doens't need any cleaning substances. It's very nice and useful for the summer time, not during the cold days.
The hot tub mentioned in the amenity list was a misunderstanding of the word. We have a bath tub and it can be filled with hot water. It has been now removed from the amenity list.
We will reduce the amount of water given to the many plants we have in the house, so that there will less or no more the tiny flies in the house. As nature lovers, we place high value on the sustainability of the house.