Indoor swimming pools need a very special environment in which to run because when the pool water is heated to 22 or 25 degrees C large volumes of moisture are released into the indoor pool room.
This is heavily laden with chlorine or bromine disinfectants, then can attacks everything in the pool room.
If left unchecked mold and mildew will eventually cover every inch of an indoor swimming pool room.
The solution is to install an indoor swimming pool water heating and dehumidification system that is designed to provide indoor pool room heating and cooling, as well as pool water heating entirely automatically.