You Can Save A Lot, When You Turn These Off !
If you have water features (waterfalls, deck jets, and even fountains) these add ambiance, but they also come at some cost. So, when not using your pool, best to turn them off.
Waterfalls will be cooling your pool water as well, meaning more heating is required.
All of them generate more evaporation and thus added costs for water and chemical replacement will be needed.
If they are part of the ambient sound, you enjoy, look at putting on a time switch or daylight sensor to reduce the power usage.
If you have a larger waterfall, maybe there is a possibility to turn off this ( when the pool is not being used) but create a mini one in the same area to maintain the sound ambiance, with less running costs.
Thinking outside the box can save you money, but maintain most of what you desire.