Does the water need to come out of the bathtub spigot? If not, you could get a pond pump (designed to pull water from a pond and pour it back in to avoid bugs a

Does the water need to come out of the bathtub spigot? If not, you could get a pond pump (designed to pull water from a pond and pour it back in to avoid bugs and algae) and use it with the bathtub or a small portable plastic pool. Hook up the pump so it draws water out of the tub or pool, hang the output hose up above it, and you'll have continually flowing water with minimal waste. The higher the gph rating of the pump, the more intense flow you can achieve. https://www.homedepot.com/b/Outdoors-Garden-Center-Ponds-Pond-Accessories-Water-Garden-Pumps-Fountain-Pumps/N-5yc1vZc9r9 https://www.homedepot.com/b/Outdoors-Garden-Center-Ponds-Pon... https://www.amazon.com/Portable-Swimming-Bathtub-Collapsible-Plastic/dp/B0CD4C1LRF/ https://www.amazon.com/Portable-Swimming-Bathtub-Collapsible...