Pool/Spa Combo, Salt and Solar --- Yikes!

Could work with a check valve installed in this new bypass line to prevent water from flowing back to the pool return line, when the spa is isolated.
This would give you a little more chlorine residual in the spa than you have now.

Now the catch (just because there's always got to be one), the amount of additional chlorine would depend on the proper check valve pound rating. I wouldn't know where to start to estimate if you need a 1/4 lb, 1/2 lb, 2 lb or larger. My guess is that a 1/2 lb would work fine.

Another question, isn't the water being send to the spa in normal mode, a matter of how much your diverter valve is adjusted? If you've got an automated valve, you can adjust the cam to open the spa mode a little more than the pool mode, so that more chlorinated water is sent to the spa.
(Here's that catch again) You'll have to watch how much you can divert to the spa because if there isn't enough flow to the manifold, the Pool Pilot will shut down down from low flow.

So, back to your suggestion with the new bypass....Nice Idea~!

Sean,

Thanks for you comments. I appreciate your willingness to be part of this discussion.

I just finished sending a new email to your office because of another issue, but back on this topic....

Yes, I also believe that the new added bypass could help increase the chlorine level in the spa. If I find I do not have the correct flow, can I change the spring in the flow valve --- I asume you're talking about the flow control valve in the SC-36 manifold? And if I can, where do I get a different spring, or is it more a matter of stretching the current one? Finally, I don't see any why to get inside that flow valve. Is it repairable, or must I buy a new manifold?

Yes, I currently can control the total bypass flow to the spa, but I run it wide right now to try and get as much circulation and chlorine in the spa as possible.

It also occured to me that if I use a dual bypass to the spa (with check valves of course) and a Jandy 3-way valve (maybe even automated) I could meter the spa water, selecting some upstream water (before the SC-36) and some downstream water (After the SC-36) to be diverted to the spa for overflow. In this way, I can better control the amount of spa water and the amount of chlorine. Just an idea, and I'm sure it's a lot more complicated than it appears.