Running separate pool and spa at same time

[Terry]

I have a fiberglass pool with a separate spa- no spillover. Although they share common equipment I have always ran them separately, which is a pain and I frequently forget to change over to the spa until I notice it looking a little hazy (or green ).

Jandy valves are used to alternate between the pool and spa. I have always turned the valves completely one way or the other to run either the pool or spa, but the valve can be set for both to be open and now I’m wondering if I can’t open both and let them circulate together.

I have a Jandy valve controlling the intake from the skimmer and main drain and I frequently move the valve to control more/less intake from one or the other. I would think I could use the spa/pool valves the same way. What concerns me is drawing too much from the spa or depositing too much back in. I can experiment with the valve, how much is open vs closed for each side, but will the water flow stay constant over time (I know the valve won’t move)? If I get it balanced can I feel confident that I can walk away and not worry I’ll come back to an empty (or overflowing) spa? It seems logical that it should work, but am I missing something?

My digital camera is not working, so here is a drawing of the pool plumbing:

 

[mas985]

You can do what you are suggesting but if you don't get it exact, over a period of time, the spa could either drain or overflow.

To equalize the flow for small amounts, you could set up a siphon between the pool and spa with a short piece of vacuum hose. The hose must be completely filled with water and placed in both the spa and pool. This will allow small amounts of water to travel from the higher body of water to the lower body of water much like a spillover. However, this will only work up to a point because of the small diameter. If the flow rate in the siphon cannot keep up with the differential, there will still be a problem. But it should be able to keep with a differential flow rate of a few GPM and probably up to about 10 GPM or so. A larger pipe would allow for a larger flow differential but then it gets harder to create a siphon.