Do I Need a Different Pump or filter by pass for Spa to work Jets?

[soleen]

Hi everyone,

I have a question about my pool setup and would appreciate some advice. My pool was built last year, and I'm experiencing an issue with the spa jets. Two out of the six venturi jets aren't producing bubbles.

Here's some additional information:

• Filter: 60 sq ft DE filter (recently backwashed and properly loaded)
• Multiport Valve: When set to bypass the filter (recirculate), all six jets work properly.
• Flow Meter:
  • With filter: 60 GPM at 3,450 RPM
  • Bypassing filter: 70 GPM

My question is:

• Should I add a filter bypass valve that activates only when using the spa?
• Or, would a bigger pump be a better solution?

Current Setup:

• Pump: WhisperFlo VST THP 2.6
• Control System: Intellicenter

If a new pump is needed:

• What size and type of pump would be recommended?

If a bypass valve is the solution:

• Do I need check valves in the bypass line?
• Or, can I simply install a pipe connecting the filter inlet and outlet, activated only for spa use?

Thanks in advance for any insights you can offer!

 

[mas985]

• With filter: 60 GPM at 3,450 RPM

What is the filter pressure at that setting?

Standard 3/8" jets require about 15 GPM each (90 GPM total) to have moderate strength. 10 GPM per jet is going to be fairly weak.

Do you know the size of the jet nozzle orifice (NOT external eyeball)?



What is the distance between the jets and the pump and what size pipe? Hopefully the PB used at least 2.5" pipe.

What is the make/model of the heater you have and does it have a bypass? Heaters tend to have a lot of head loss.

What is the pipe size for the multi-port valves? Multi-port valves tend to have a lot of head loss.

 

[soleen]

Thank you for your reply, my answers below:

What is the filter pressure at that setting?

When the pump is running full speed filter pressure is 30-35psi

Standard 3/8" jets require about 15 GPM each (90 GPM total) to have moderate strength. 10 GPM per jet is going to be fairly weak.

Do you know the size of the jet nozzle orifice (NOT external eyeball)?

Originally, I had 7/16" orifice nozzles installed. However, about two weeks ago I replaced them with smaller ones: 5/16". Before this change, I barely could get any bubbles at all. With 5/16" 12 GPM (6 * 12 = 72GPM) seems to be enough to generate bubbles, but 60GPM is still not enough to generate bubbles in all jets (only 4 are working with 60GPM).

View attachment 571154

What is the distance between the jets and the pump and what size pipe? Hopefully the PB used at least 2.5" pipe.

Unfortunately, they used 2" pipe, but the distance is short, see attached image.

What is the make/model of the heater you have and does it have a bypass? Heaters tend to have a lot of head loss.

Pentair MasterTemp 400k BTU, it does not have bypass.

What is the pipe size for the multi-port valves? Multi-port valves tend to have a lot of head loss.

Multiport is 2"

 

[mas985]

By regulation, 2" pipe should not exceed 63 GPM in the suction pipe (6 ft/sec). Unfortunately, too many PBs make this mistake and it is nearly impossible to work around. Just keep in mind that entrapment risk increases with flow rate.

But you will gain some flow rate if you put in a true bypass around the filter AND heater. The multi-port does not bypass itself so not a very good solution. Something like this should improve things a bit:

 

[soleen]

By regulation, 2" pipe should not exceed 63 GPM in the suction pipe (6 ft/sec). Unfortunately, too many PBs make this mistake and it is nearly impossible to work around. Just keep in mind that entrapment risk increases with flow rate.

But you will gain some flow rate if you put in a true bypass around the filter AND heater. The multi-port does not bypass itself so not a very good solution. Something like this should improve things a bit:

Thank you, for the suggestion, I will look into doing this.

View attachment 571172