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

[CalMan]

My pool is 15,000 gal and my spa is 700 gal. In pool mode, the spa overflows into the pool, therefore the autopilot chlorinates spa and pool to the same ppm's. In spa mode, there's only circulation in the spa, and the autopilot does not come on.

I also have solar and when in pool mode it heats the spa and pool to the same temp. In spa mode, it only heats the spa.

The autopilot and solar work against one another.

I'd like to keep the spa at a higher temp than the pool and I'd like a higher chlorine concentrtion in the spa, but I can figure out how to do it.

I run the pump in pool mode for 3 hours and in spa more for 3 hours each day, while the sun is shinning. The pool is heated to almost 80 and the spa reaches about 95 --- solar is working great!

The autopilot only runs when in pool mode and therefore the three hours in pool mode brings both the pool and spa to about 3ppm's of chlorine. I'd like to keep the pool at 3 ppm's and raise the spa to about 5ppm's. If I run longer in pool mode I will get a higher overall chlorine concentration, but lose heat in the spa. If I run it longer in spa mode, I will get more heat in the spa, but the overall chlorine concentation will drop. Basically, I can't figure out how to get different chlorine concentations in the the pool and spa and heat the spa to a higher temp than the pool.

Has anyone else experienced this problem and what have you done to solve it?

Thanks,

al

[waterbear]

a schematic of your plumbing system would be helpful to figure out what is happening. I have a pool spa combo and it is plumbed in such a way that I can have the suction and returns go to the pool only, the spa only, or run in spillover with the returns going to the spa and the suction in the pool. My Goldline Aqualogic will chorinate in any of these settings (and allows me to select differant chlorine outputs and pump run times for for the spa only mode vs pool only or spillover and my heatpump will bring the spa to a higher temp when in spa only mode because the Aqualogic automation allows me to select different thermostat settings for each. It will work exactly the same if I had solar insted of a heatpump. Do you have a separate pump for running in spa only mode or are you selecting the different operating modes with valves or actuators? It seems that the problem you are having might stem from the way the system is plumbed. There is more than one way a pool/spa combo can be plumbed and some offer more flexibility than others. More info would be useful to help determine what is going on. One possible solution (although a pricey one) might be an automation system that will allow you to select these different settings for the different modes of operation if the equipment that you currently have cannot.

[cschmelz]

Just be aware a lot of times they intentionally turn off the salt water cell when you are in spa mode to prevent overchlorinating the much smaller water volume of the spa versus the very large volume of the pool..

I think you are going to have some real problems with overchlorination (perhaps 5+ppm in the spa) if you have equal run times for both pool and spa...

[Poolsean]

Your plumbing is correct for a pool spa combo. Why do you want to hold a higher chlorine level in your spa? How often do you use your spa?

[CalMan]

Thanks for you help with this issue.

Here is a bit more info.... My system uses a single 1 hp pump for all circulation with Jande valves to control flow from the suction, to the return and to the solar. I know I could use an additional pump for solar, but the solar works so good right now, I hate to change that part. My concern is maintaining the proper chlorine level in the spa.

On the return side, the return valve directs water either to the pool or the spa, with a bypass line (which I manually control) to allow some of the pool water into the spa. The Pool Pilot is plumbed into the pool return side only. Therefore, chlorine is injected into the pool only. The spa is never chlorinated directly, it is chlorinated by water that eventually circulates from the pool through the bypass line to the spa. In this way, if I run the circulation pump long enough in pool mode, the spa will reach the chlorine level of the pool, but never any greater. If I do not run the pump long enough, the spa will not reach the chlorine level of the pool. At present, the highest level of chlorine I ever see in the pool and (at best) the spa is about 3 ppm's.

I have read that the spa should have a higher concentration --- as much as 6 ppm's. This is the first year for this pool/spa and the kids (and grandkids) find it a fun place to hang out, therefore it's getting alot of use. In a typical week, it's used 4 days for about 6 hours and the kid load is big.

I could have the plumbing changed and move the pool pilot behind the return valve, which would allow chlorine to be injected into the water whether in pool, spa or overflow mode. If I do that, chlorine will be injected into the spa and I could control the amount by the length of time I run the pump, but it also means that while bathers are in the spa, chlorine will be injected. Since the Jande RS-8 controls the pool pilot, it would be nice if the Jande could set the percent of chlorine to two different rates --- one for the pool and one for the spa. Is that possible?

How are others using their chlorine generator with a pool/spa combo? And how do they control the amount of chlorine in the spa versus the pool?

Thanks for any comments....

[waterbear]

I have an aqualogic PS-8 chlorinator/automation system and the cell is plumbed before the valve that selects return to the pool or spa. The Aqualogic does allow for different settings on the chlorine output for pool or spa and pump run times for each. This allows me to keep a slightly higher FC level in the spa than in the pool. In spillover mode it uses the pool settings on the chlorine generation. The valves are controlled by acutators so the whole process is pretty automatic. Don't know if your Jandy/Autopilot setup will allow that but if it does moving the location of the cell might be the answer. If it is possible to have a lower cell output when in spa only mode the chlorine going into the spa while it is in use would not really be an issue. My cell is operating at 3% when in spa only mode.

[Poolsean]

The AutoPilot does not interface with the Jandy to reduce the output. If you plumb the manifold before the diverter valve, you will need to adjust the output setting lower when you use the spa.

[CalMan]

Sean,

The inability to dynamically adjust the Pool Pilot for pool mode versus spa mode is a severe limitation. I understand the Aqualogic can make that dynamic adjustment.

Are you saying the pool pilot is not suited to pool/spa combos, because there is no way to insure the amount of chlorine in the spa? There must be a way...

I'm sure the program in the Jandy and Pool Pilot can be changed to allow for dynamic adjustment. The Jandy can change the percent of chlorine being injected by the pool pilot now, just not when moving between pool and spa mode. It would be necessary to add a menu item to set the spa percent in the Jandy, and then detect when in spa mode to send that spa percent down to the Pool Pilot....

I'm willing to be a field test site for Jandy and Autopilot, if they are willing to improve their products.

Wil

[salinda]

I also have a pool/spa combo but I heat my spa with the gas heater only when we use it. I let the overflow take care of chlorinating the pool and spa together. I think you are looking for a higher free chlorine concentration in a typical spa because bather load is higher due to smaller water volume, but with an overflow 3 hours a day, you are greatly mitigating this issue. You are not constantly recycling the spa water but you are moving fresher, lower bather load water, back into the spa during pool mode. I am no expert, but I do have a technical background and I don't think the chlorine difference you are looking for is a huge issue. The biggest benefit of the swg in this situation is that WHILE you have heavy bather load in the spa, you are getting the higher chlorination just while you need it, when it is in spa mode.

[CalMan]

Thanks for your reply --- you got me thinking...

With my current plumbing, in pool mode, water is drawn from the pool skimmer, filtered and heated (either solar or gas) and it then enters the return diverter valve and is directed to either the pool return or the spa return lines. The SWG sets between the return diverter and the pool return lines. When the SWG is on, it injects chlorine into the pool return line, but not the spa return line. The spa bypass draws water upstream of the SWG, and therefore the spa is never chlorinated directly from the SWG, it gets chlorine by replacing spa water with pool water. If I filter and pump long enough the spa water will be replaced with pool water and approach the same FC level.

I've been considering moving the SWG upstream of the diverter with requires two chlorine settings, one for the pool and one for the spa, but you gave me another idea.

What if I added a spa bypass line downstream of the SWG? Doing this would allow me to send some of the chlorinated water directly to the spa. In other words, with the new bypass line closed the system would work as before. With the new bypass line open, the spa would receive additional chlorine directly from the SWG. Depending upon how much water I diverted from the SWG would determine the higher chlorine concentration in the spa. In spa mode, no chlorine would be injected.

Comments appreciated....

[Poolsean]

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~!

[CalMan]

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.