Spa turnover vs pool

[300winmag]

Not sure where this should go, but since a SWG is involved I stuck it here. Feel free to move it if need be.

Some background on my pool setup:
I can run the spa in spa-only mode (only the spa has return and suction).
I can run the spa such that its floor return feeds water in, and then the overflow goes over a spillway into the pool, and the pool has all of the suction.
I can run the pool such that it gets all of the return and suction (spa has zero flow).

The 3rd option above is now possible due to a 4th actuator being installed. I can control the spillway via a schedule (even if it currently turns on/off with a tanning ledge bubbler), so I am wondering how much turnover my spa needs. Of course, the PB says that my spa will turn green if I don't circulate it all day. But that seems pretty excessive...

My question is, is there a ratio or calculator to determine the amount of time/turnover the spa needs? If the spa is 1/32 the size of the pool, does it need 1/32 of the flow that the pool receives (not time, but volume of water)? Or is it trial and error, and just see what works?

Thanks

 

[mas985]

You just need to run it long enough to get the FC level to it's proper set point. Try 30 minutes and test afterwards to see if the FC level is high enough. In the past, I have run mine for only 15 minutes in spillover mode and that was more than enough to get to FC levels.

 

[cdchris1]

I have a very similar setup. I would think trial and error would be best, since the use and sun exposure are probably different than the pool. Originally, I had my spillovers set to run 20 minutes once a day. That was not enough and I kept ending up with no chlorine in the spa. I have since set them to run 20 minutes, 3 times a day and my FC levels are good.

 

[mas985]

It does depend on the SWG setting too. If the SWG setting is so low it shuts off during part of the spa spillover run time, you are kind of wasting run time. Personally, I set my SWG high enough so that doesn't happen and I can get away with as short of a run time as possible. The IC40 should produce about 3 ppm in a standard spa over 20 minutes if it is running constantly. That should be more than enough unless the spa had zero FC to begin with but then you have a different problem.

 

[300winmag]

The IC40 should produce about 3 ppm in a standard spa over 20 minutes if it is running constantly.

Is that assuming full flow to the spa? In my case, I would run the pool and spa together so the spa would likely be getting ~1/4 of the flow from the SWG.

EDIT: I just tested after 60min of run time, and the FC in the spa came up 1.5ppm.

I'll keep testing, but it looks like with my setup and current weather conditions 1.25hrs of spa flow per day will keep me where I need to be

 

[mas985]

If you bring your pool up to your FC target first (run spillover after pool mode), then you can run the spa a lot less to get it up to the target. Then the flow rate from the pool is the primary source of chlorination instead of the SWG itself. If you run them together, then you basically are treating them as one body of water and run time will be dictated by the combination of the two.