Spillover spa - Is it possible


Well-known member
Jul 10, 2007
OK, I am new to the forum, first post. I am in the process of talking to builders and designing my pool. So far, pretty frustrating process, as I am getting very conflicting information from everyone on about everything, and I am very much a researcher for everything I buy, and I am trying to buy like 60 things at once!

So, in my design now, I think I want to build a spillover spa. I "thought" I read that this can be a great add on feature because you can use the same equipment as your pool, thus saving on a heater, pump, and additional chemical testing. My potential builders are telling me that I have to have all separate equipment, which of course is a significant cost, and second, they are telling me that the plumbing is going to be insanely more expensive as well (don't have exact quote, but they are saying like 15K to add it to my pool!)

So, my questions. Is the builder right, or am I right on the equipment need? I know the plumbing has to be done so that I can winterize the pool, and still use the spa, but is it really that hard? And finally, Is adding a spillover in Ohio a bad idea?

Thanks for your thoughts... Chuck


Mod Squad
TFP Expert
Apr 4, 2007
SW Indiana
I can't imagine having a spillover or shared plumbing in freezing climate. I'd guess that with clever design you could share the equipment while still winterizing the pool's portion of the plumbing, but you'd have to run the spa and heater 24/7 whenever the temperature was below freezing. You'd also have to plumb an alternate method for returning water to the filter during cold weather so the spillover can be disabled. Your heat bill will be pretty darned high.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Yes it is possible, but there are compromises. If the plumbing is in common the spa needs to get drained when you close the pool, which also means the spa has to be a little higher than average. If you want the spa open when the pool is closed then you need to have separate systems.


LifeTime Supporter
Jun 4, 2007
I have two separate systems for my pool and spa and it was a bit more costly but I like the benefits you get from it. I also have a faux spillover that makes it appear that my spa is spilling over but it's really just another pool return.


Active member
Apr 15, 2007
Well aside from winterizing, which I'm not familiar with being in AZ. It is very possible to share equipment with a spillover spa and pool, in fact your spa doesn't have to be spill over to share equipment. The only advantage of the spill over is that in case you turn the valves wrong you won't be spilling over into the yard and drain your pool, that is if you are taking the suction from the main drain of the pool and pumping it back into the spa.

I have a 18" raised spa with spillover that shares the same equipment. My spa is pretty large in size about 10' by 6', shares the same pump and filter. I only have an extra pump for my waterfall. The extra cost of the plumbing and spa for my pool was about $8,800, it's a 1,000 gallon spa.

Sounds to me like the pool builder you're quoting must really like selling extra equipment or they are just not as comfortable plumbing two systems together.



LifeTime Supporter
May 10, 2007
Baton Rouge, LA
Sounds like a regional thing to me.

In south Louisiana, the norm seems to be to share one system... then again, freezes are rare, and many people never close their pool/spa.

One thing you'll learn quickly about pb's is that they want to sell you what they're comfortable with. Two systems keep it simple, and keeps them from making mistakes... not to mention the extra eqmnt sales.

To have 2 almost independent systems, or really three systems (spa for winter, pool + spa for summer) sharing one set of equipment would mean custom calculations, and a pretty smart fellow to figure out... they don't have time for smart (and less money)... therefore... you'll have to figure it out yourself if you really want it.

I bet you can... just some good math and a bunch of valves...

Just build your equipment pad big enough to split it up and add pumps if you get it wrong...

You thought this would be easy, huh?

By the way, read this and other forums a few weeks and you'll be a good bit smarter than your builder... if you could only combine his experience and your knowledge... you could be reallllly dangerous.

Good luck!


Well-known member
Jul 10, 2007
Thanks for the info all. I think I agree on the regional thing and the "comfort" level. I think I have backed off of the idea now.

As for reading, This forum has been incredible. I think I already know more about certain things than the PB, which is kind of scary.