Thank you for your inquiry. There are two primary ways to plumb a pool and spa combination:

Shared Equipment System: This setup uses automatic valves to switch between Pool Mode and Spa Mode. It’s more cost-effective upfront since the pool and spa share the same equipment. However, heating the spa takes longer because the water starts at the pool’s temperature.

Dedicated Spa Equipment: This option provides a completely separate set of equipment for the hot tub. It offers faster heating and independent operation, though it comes at a higher initial cost.

Regarding the waterfall feature, it can be designed as a true overflow from the spa into the pool, or plumbed with a dedicated return line. The latter allows the waterfall to run independently of the spa system and pairs well with the separate equipment setup for a cleaner, more controlled aesthetic.

I hope this helps answer your question.

Thank you very much