Spa "return(s)" versus spa "jets"

[waterbear]

Sometimes in a shared system the spa jets use a booster pump to supercharge them. Sometimes a blower is used for this also. In either case the main pump needs to be running and the valves need to be in the spa position. Usually when there is a second pump for the spa only it also has separate filtration, heat, and sanitation and works independantly of the pool system.

[imfignewton]

If you can afford and have the room two seperate systems one for the spa and one for the pool is the best way to go. Just have a valve for suction from the pool for spillway overflow. Put in a spa side remote with temp. readout.

[eljefe281]

Sometimes in a shared system the spa jets use a booster pump to supercharge them. Sometimes a blower is used for this also. In either case the main pump needs to be running and the valves need to be in the spa position. Usually when there is a second pump for the spa only it also has separate filtration, heat, and sanitation and works independantly of the pool system.

This gets to the central point of my question.

If there is a "booster pump", is it located in series with the main circulating pump (after the pool/spa diverter valve on the pump discharge)? That I could understand, although it would seem strange to me.

Or is it in parallel? If it is in parallel, I don't see how the main circulating pump and the booster pump could pump through the same returns/inlets/jets.

What makes sense to me is this:

Spa jet pump and spa blower are plumbed altogether separately from main circulating system (separate set of spa main drains - no diverter valves anywhere in this circuit).

While using the spa...

...pool/spa diverter valves in the main circulating loop - both suction and discharge - are in spa position.
...main circulating pump is running.
...heater is operating as needed to meet temperature set point.
...main circulating water is coming into the spa through a non-jet return.
...spa jet pump and spa blower are pumping/blowing into the spa through the jets.

[imfignewton]

Some spas are set up to use the circulation pump as the booster pump.

Diverter valves would turn for suction from the spa drain to the circulation pump to filter to heater to spa jets with air venturi. In this configuration you would have a return to the spa but it would be used to divert some of the pool return for sanatized water to the spa then over the spillway. Do not set up your spa this way. Use a dedicated booster pump and blower with spa jets (example Waterway Poly Gunite Spa Jet). Do not put in pool return inlets as spa jets.

When you have dedicated booster pump and blower to the spa, you will still have pool return water diverted to the spa and over the spillway for sanitation.This setup is for shared circulation pump, filter, heater and sanatizer.
Look at this link for a simple pool spa diagram page 8
www.jandy-downloads.com/pdfs/6594.pdf

[waterbear]

My system is set up with one pump, filter, heater for spa and pool. My automation can select spa only, pool only or spillover mode. My blower is connected to a bubbler ring in the spa and can operate whether the valves are in spa, pool, or spillover mode.. When in spa or spillover mode I have venturi air injection to superchage the jets via control valves on the spa. I am more statisfied with this spa then with the stand alone spa I used to own. I only turn on the spillover when I want a water feature, when adding chemicals, or to replace the water in the spa after heavy use. The spa and pool are chlorinated to different levels by my SWG...once again selectable from my automation (Goldline Aqualogic PS-8)