Spillway needed or not with Magic Falls on spa wall?


In The Industry
Sep 14, 2021
I’m in construction and everyone says I will need a spillway for my attached spa. Won’t the spa water blend/filter with pool water through the drain/infloor?
One of the spa/pool walls will have a magic waterfall going into the pool. I can add a spillway on the other wall but prefer not to if possible. The spa doesn’t have its own filter and the CMP waterfall is on a booster pump.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

The only way water can get from a normal spillover spa and back into the pool is via the spillover. There is no "mixing" via the floor drain. It is not at all how pool automation systems are designed..

That said, you can call a spillover anything you want, as long as the spa water overflows back into the pool when in the Pool mode. When in the Spa mode the water should be lower and no longer overflow into the pool.

You can have two separate systems.. one for the pool and one for the spa. Each system would have its own pump, filter and plumbing. If you have two systems, you would not normally mix the pool and spa water to prevent the pool from emptying the spa or the spa overflowing. Two systems would mean you would have to chlorinate both bodies of water separately.

The whole purpose of a spillover spa is so that the spa water stays chlorinated and fresh.

How do you intend to switch between the Pool mode and Spa mode???


Jim R.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Welcome to TFP.

What is this “magic waterfall going into the pool”?