Building new concrete pool and spa. Should the SPA spill over?

[Abe]

Hi,

My wife and I are building a new house with salt water pool and spa in Florida.

The builder is giving us our choice of whether or not to have the spa spill over into the pool. The pool and spa are adjacent to each other each made of concrete and essentially will be the same in appearance except for what ever we decide on regarding a spill over.

What are the advantages, or disadvantages to having a spill over vs not?

The builder says if he was building it for himself, he wouldn't do a spill over, as it is more energy efficient, it is easier to just keep the spa up to temperature, and the spa will heat up much more quickly. That makes a lot of sense to me. It makes no difference in our cost if I do the spill over or not. So I am leaning towards not doing the spill over.

Is there anything I am missing or other concerns/advantages, etc?

Thanks!

 

[Divin Dave]

Hi Abe,
Welcome to TFP! I will just through a couple of things out here for consideration.

First, if your spa is seperate from the pool, then you will have two seperate bodies of water to maintain.
A seperate spa with a few hundred gallons of water is more difficult to maintain proper chemistry than a large body of water with many thousands. Often the chemicals are are even completely different, for example, chlorine to sanitze the pool and bromine to sanitize the spa.

With a spillover, the pool water flows into the spa, and so you only have 1 body of water to keep algae free and sanitary. And maintaining a pool is easy, if you know how. (recommend to start reading Pool School now, so you arent behind the 8 ball when the pool starts filling up with water).

If the plumbing and valves are designed correctly, you can isolate the water circulation to the spa only and in being able to do so, only heat the spa water making it as efficient to heat as a stand alone spa.

If there's a downside to a spillover, its that the pH of the water will rise quicker, because water spilling over into the pool aerates the pool water, which causes the pH to increase. That said, the pH rise can be minimized if you know how. (again, see pool school and read lots of posts here on the subject).

Im sure some others will chime in too....

enjoy.

 

[Abe]

Hi Abe,
Welcome to TFP! I will just through a couple of things out here for consideration.

First, if your spa is seperate from the pool, then you will have two seperate bodies of water to maintain.
A seperate spa with a few hundred gallons of water is more difficult to maintain proper chemistry than a large body of water with many thousands. Often the chemicals are are even completely different, for example, chlorine to sanitze the pool and bromine to sanitize the spa.

Thanks for the info Dave. Both are to be salt water. so I'm not sure about their being different chemicals involved. But I do understand the 2 separate bodies of water. It would seem that is a pitfall worth looking into.

I guess the question is: Is the gain in efficiency in heating the spa worth the trouble of having to maintain 2 separate bodies of water? I've never had a pool before, so I really do not know.

 

[Divin Dave]

Abe,
hummm... So if both are the be saltwater, then Im suspecting the PB is indeed planning on using pool water to populate the spa with, thats the only thing that really makes sense.

The salt in pool water is used by a Saltwater Chlorine Generator (SWG), to make chlorine, so both the pool and spa will be chemically identical.

A stand alone spa using its own water are usually maintained by using Bromine instead of Chlorine. That's why I mentioned different maintenance needs. Not so in your case so it seems. Caveat here, it would be helpful to know the plumbing layout to be 100% sure.

But to answer your question about heater efficiency, and this with the understanding that the spa will be using pool water.

I dont see any difference between the spill over and the non spillover if it is plumbed properly.
There should be valves at the equipment pad that you can turn to close the circulation on the pool, and open others to circulate only water to/from the spa through the heater.

If the plumbing and valve set up can do this, then it doesnt matter if the teh spa is a spillover or not, the heating efficiency would be the same either way as long as you are heating the spa only.

Here is an example of the plumbing and valves that I mention. On this set up, the 3-way valves on each end control the circulation. In one position, it can block all circulation to and from the Spa an donly draw from the pool. In another position, it can block circulation from the pool and draw only from the spa, and in another position, it can draw circulation from both.
20150809_101320_zpswcvx6oc0.jpg Photo by divindavedunkin | Photobucket

 

[ummgood]

Plus I would add in addition if you are very concerned about having the spa totally disconnected from the pool and would have to maintain it separately with different chemicals then it would probably be better to have a stand alone spa. We might do that in the future because we could put it up on our covered porch so it easy to get in and out in the winter.