Are there any plants that would thrive in the atmosphere of an indoor swimming pool?
Anything that enjoys a humid atmosphere would love it. For example, if you want something large, try a Swiss cheese plant.
I imagine Orchids would like it, providing they are not in full sunlight for the majority of the day. There are many types and they mostly enjoy warm, wet shady places. I have one on a N/E facing windowsil in my bathroom and it loves it there.
Thanks for your comments but I am a bit concerned that the atmosphere may contain too much chlorine .Any thoughts
If chlorine levels were high enough to damage plants, they'd be dangerous for people, too, so I wouldn't worry about it. To be detectable by our noses, only 0.5 parts per million of chlorine in the air is needed, which is a very tiny amount - our noses are extremely sensitive to the gas.
I can smell chlorine in London water when I visit and I'd have thouught you need rather more than that quantity in a swimming pool purification system unless you go for something more modern.
I'd have though most tropical origin houseplants would do well in the warmth and humidity so ficus elastica, ficus benjamina, anthuriums and so on.
I too don't think chlorine would be that much of a problem, especially as we're talking a small amount in the air rather than on the roots or leaves of the plants.
Here's another suggestion, Fuchsia Thalia.
Hoyas are lovely and can grow to be pretty large
My first thought is 'what are the light levels like?'. If it's surrounded by glass and the light levels are good that's great but if the light levels are low that will limit your choice.