Inground spa jets not air bubbling

[Vowial]

I’m looking for some help and or advice regarding the jets of my in ground spa.
The air 6 spa jets have been running fine with all of them bubbling.
A few weeks ago 5 out of the 6 jets stopped bubbling.
The pump is a Pentair 3hp running at full speed (3200rpm) and filter is completely clean.
I drained the spa and when refilling it I observe the following: All jets are working well generating powerful stream and bubbles. As soon as the water level submerges the last jet all of them stop bubbling except for that last of.
So far the troubleshooting I’ve done is:
A) drawing spa. Removing all jets with tool making sure there are no obstructions and performing visual inspection of jets. Nothing obvious was found
B) using wire to reach inside jets to possibly remove any debris
C) hooking up electric garden blower at jet air supply inlet. Blocking off all jets except for one at a time and blow air through system to remove any blockage.
None of the troubleshooting has helped so far.
Does anybody have any advice of what could cause this jet issue and how I can fix it?
Any help would be greatly appreciated.
I attached a few photos for clarification.
You can see the jets working well when filling the spa. You can see bubbles up until the last jet gets submerged. Then no more bubbles.
Thank you very much
Alex

 

[ajw22]

Welcome to TFP.

Show us pics of your equipment pad and the spa air intake.

 

[Vowial]

Welcome to TFP.

Show us pics of your equipment pad and the spa air intake.

Here are some pictures of my setup. Equipment is about 3 years old. Distance between pump and jacuzzi is about 25’. All pipes are going underground slightly sloped downward towards jacuzzi.
Thanks for your response and help!

 

[wireform]

As soon as the water level submerges the last jet all of them stop bubbling except for that last of.

That sentence sort of directs me to think you have an obstruction in that air pipe at the equipment pad because until the last jet is covered that jet is giving the air. Once it's submerged that's the end to the air supply therefore the air pipe must somehow be blocked possibly a rodent climbed in......

 

[Vowial]

That sentence sort of directs me to think you have an obstruction in that air pipe at the equipment pad because until the last jet is covered that jet is giving the air. Once it's submerged that's the end to the air supply therefore the air pipe must somehow be blocked possibly a rodent climbed in......

It’s absolutely possible that the air pipe is blocked. As you see from the photos the installer didn’t cover the intake with a mesh to prevent things from entering.
Why doesn’t the blockage cause all jets not to work right away and not only when that last jet is fully submerged when filling up the spa? I’m just curious and maybe you know the reason.
Is there a certain procedure used in the industry to detect / find a blockage in a pipe and to remove it? What tools/instruments do they use?
Thank you!

 

[mas985]

When was the last time you cleaned your filter?

What is the clean filter pressure and what is the filter pressure right now?

Also, to properly help you, it would be beneficial to have your signature filled in with your all your equipment.

Create Your Signature - Further Reading

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