Should a new spa share water with pool?

Greetings experts,

I would like to build a gunite hot tub near the pool. (My wife thinks
we should get a pre-built fiberglass jacuzzi, which is strange because
I am usually the frugal one.) It seems to me that it would be nice
to share the pool recirculation pump, filters, heater, and chlorine
generator between the pool and the spa, using a diverter. Since
every time the diverter changes position there will be some mixing
of water (mostly from the filter housing), I don't expect that I
can maintain different chemistry for spa and pool. Is this acceptable,
and is this overall a good or bad idea?

Thanks!
Luigi

I have a 6600 gal fiberglass pool and a 300 gal spillover spa next to it. the both use the same pump, filter, heaterpump, salt generator, etc. I use an Aqualogic control system which allows me to have different pump run times for the pool and the spa and to have different temperatures and chlorine generaton levels in both automatically. When I want to change the water in the spa I just turn the spillover on. (Usually for about an hour after we have used the spa.) it has been in operation since Thanksgiving and never closed since it never got cold for more than a weeks time here in FL. So far there have been no problems! I used to have a stand alone spa and the water balancing and the need to be drained and refilled every few months was a real headache by comparison!

Thanks, I realize now that I have two options: 1. recirculate the water through the spa only; 2. recirculate the spa water through the pool (the equivalent of a spillover tub). I suppose that in the latter case the organic deposits into the spa will be greatly diluted, but it will take longer to bring the spa to temperature, and I will have to control carefully the flow through the tub or it may never reach temperature.

Any other opinions?

My setup uses 3 way jandy valves for pool only, spa only or spillover operation. (they are automated by my aqualogic control system) in pool only mode the drains and the returns go to the pool, in spa only mode the drain and return to to the spa, in spillover mode the dains in the pool are on and the returns to the spa are on. I have a heatpump that brings my spa to 104 degrees in about 15 minutes from pool temp in spa only mode during the winter here in N FL and allows separate settings for pool and spa temp. In spillover mode the spa is at pool temp (85 degrees) I usually do not operate the spillover unless I have has a lot of spa use, the waterlevel in the spa is low, or if I am adding chemicals. Not sure how you could plumb it if the spa is not physically located right next to the pool and has a spillover but it probably can be done.

This is something I've wondered about. We have a new (Oct 2005) IG pool with attached spa. Is there any ill effects of running the system in "spill over" mode all the time? Should I be running it so all water returns to the pool only? We use the spa once a week or so. Thanks...

only in losing the heat in the spa, water from evaporation from the waterfall and reduced circulation in the pool from the return jets being off. You can adjust the return valve so that when it is in the pool position it just trickles water into the spa to keep a fresh supply of water in the spa but still keeping a good supply of water going to the pool returns (automatic actuators like the Goldline allow this by adjusting the cams in the actuator). This might be the best of both worlds if you don't care about the heat loss in the spa. That way when you put it in spillover position you will get fulll spillover operation and in pool position you will get some spillover but still good water circuation in the pool. It takes a bit of tweaking the postion of the return valve to get it just right. I elected for total shutoff of the spillover in pool position since I use solar covers on both the pool and spa and that makes it a bit difficult to leave the spillover running all the time!

I'm assuming your pool is already in. You should get some prices on what a gunite spa will cost. When I had my pool constructed my builder told me $4,000 to add the spa while the pool was built. The price adding it after was 3 times as much as he has to bring out all the same subcontractors just to build a little spa. Do you plan to close your pool during the winter? If you do a free standing spa may be a better idea as you can leave that running during the winter. I wonder if you can get a freestanding spa that could be set in the ground? Access to the mechanicals may be an issue for this approach.

Luigi,

There are several ways to do a pool and spa combo. If the spa is a stand alone (fiberglass or concete), you need to separate filtration systems, one for spa and one for pool. That means two of everything...

With a spillover spa, you share the filter, and pump. While the pool pump is running the water from pool returns to the spa and spills over. That keeps your spa clean and you dont have to worry about controlling the chemicals in two bodies of water.

You can have a one pump system or two pump system.
With one pump system the water is drawn from pool main drains and returned through pool inlets. Some of the water is also returned through the spa creaing your spillover. To use the spa two valves are turned, either manualy or with a controller such as Jandy, and the suction changes to spa maindrains and returns trough the spa jets. The spillover stops and now you can heat your spa. With a two pump system, the pool pump draws from pool main drains and returns trough inlets in pool and spa and a second pump is for spa jets.

Hope this helps.

Zina
www.pooldesign.net