Flush Spa piping diagram

[elier99]

I'm planning on starting the construction of a pool with flush spa during the upcoming weeks. The current plan is to use a single Intellifo3 pump and Intellichlor SWG for the water circulation/chlorination. The attached diagram shows the planned pool/spa piping and valve diagram. One of the Intelliflo3 relays will be used to switch between Spa and Pool mode (energizing the diverter valves actuators), the heater will be manually switch on at this point. The system will consist of 6 pool returns (one of them inside the Spa) and 6 spa venturi jets. When in pool mode the return inside the Spa should circulate and chlorinate the Spa water forcing spa overspill, when in Spa mode the water should circulate and heat the spa water only.

I would appreciate your feedback on the following:

• Is it appropriate to install one pool return inside the spa to circulate spa water while in pool mode?
• Is a Pentair Intelliflo3 3HP pump appropriately sized for 6 spa water jets? No spa blower is currently planned.
• Can the Intelliflow3 control the Intellichlor output % from the selected program? The plan is to use the RS485 comms in standalone mode to communicate with the Intellichlor SWG cell (no further automation is planned at this point).

Any further comments or recommendations would be appreciated.

 

[ajw22]

I think you want the SWG before the diverter valve to be able to chlorinate the spa during use.

The spa is a small water volume and high bather load that will consume FC during use. If the spa is used for any length of time all the FC can be consumed. You need to add FC from normal pool levels to keep the spa sanitary during use.

 

[flynwill]

I have a flush spa with 6 jets running off a single Jandy 2.7 HP VSP, so i would expect that with properly designed plumbing, the 3HP Pentaflow should be fine as well. Someone (you or your contractor) will need to do the head loss calculations for the setup to be sure.
You don't need a dedicated return for the SPA, As ajw22 says the SWG should be between the heater and the distribution valves. To provide makeup water for the SPA the diverter valve can be adjusted so that the spa jet line is not fully closed in pool mode. It is easy (at least easy on my setup) to adjust for a steady flow of water over the SPA dam but not enough to pull any air into the venturis of the jets.
I realize it's a significant added expense, but I would strongly recommend adding automation for a SPA pool combo, which makes turning on the SPA a matter of pushing a button and waiting for it to head up. Versus turning two valves by hand, switching the pump to higher speed. and adjusting the heater temperature set-point.

 

[mas985]

It looks like you have a "pool return" going to the spa? Instead, I would put in a second return loop in the spa so if you decide down the road to have a separate spa jet pump, the plumbing can accommodate that.

Also, I would make all suction lines at least 2.5" and the spa jet lines at least 2.5".

I would skip the MD. They just steal flow from the skimmers and don't add much value. If you are concerned about circulation in the deep end, a deep return is a better choice.

Also, if you plan on using one pump, I would go with a cartridge filter over anything else.

 

[JJ_Tex]

I have a flush spa with 6 jets and the same Pentair pump you have. My plumbing is like yours, with the tweak that Allen mentioned in post #2.

The pump is plenty big for the spa and 2,000-2,500 RPMs gives me all the spa action I want. The only time I wish I had a 2nd pump was on the pool water features. If I run those (rarely) I have to partially close off the valves to the return and run the pump at 3,000+ rpms to get good water flow out of the water features.

 

[elier99]

Thanks all for the feedback!

Running in SPA mode with the SWG with this configuration wouldn't the FC levels to rise too much? Would this require lowering the SWG output while in SPA mode?

Below updated diagram.

 

[ajw22]

Running in SPA mode with the SWG with this configuration wouldn't the FC levels to rise too much? Would this require lowering the SWG output while in SPA mode?

Below updated diagram.
View attachment 510365

Depends how many hours you stay in SPA mode.

Run the numbers how long it would take to get the spa from normal pool FC levels to over SLAM FC levels with CYA of 70-80.

 

[mas985]

Are you using any automation? I have a separate spa and pool setting for my SWG.

 

[elier99]

Depends how many hours you stay in SPA mode.

Run the numbers how long it would take to get the spa from normal pool FC levels to over SLAM FC levels with CYA of 70-80.

Great approach! If an IC30 is used at 50%, it will take about 7 hours to get from normal to SLAM levels considering the SPA volume of 700gal. It seems it shouldn't be an issue then.

 

[elier99]

Are you using any automation? I have a separate spa and pool setting for my SWG.

Not initially, will use the Intelliflo3 relays to control the valves to change from pool mode to SPA mode by using a Manual Program.

 

[ajw22]

Great approach! If an IC30 is used at 50%, it will take about 7 hours to get from normal to SLAM levels considering the SPA volume of 700gal. It seems it shouldn't be an issue then.

 

[JJ_Tex]

Not initially, will use the Intelliflo3 relays to control the valves to change from pool mode to SPA mode by using a Manual Program.

If you do decide to go with automation, you can have different outputs to the various bodies of water. In spa mode mine maxes out at 20%, but the pool can go all the way to 100%.