That does sound like the pressure gauge is not reading correctly. Most systems will show an increase in tank pressure when the spa is on, especially on a 4 jet system where 3 appear to be weaker.

Did this suddenly start happening?

Is the one jet that is the champion drawing air too?

If you were to lower the spa's water level to just below the jet height, is the champ is still the champ or are they now equal?

Is your pool new? Did you have the pool built? Is this a concrete pool, liner pool, or fiberglass?

Scott

My "DE Filter" pressure guage usually goes up 10 psi above its normal operating level, as soon as I divert the water flow over to the spa.

I don't recall how things were before, but I can't imagine I would have been satisifed with the performance when only 1 of the 4 jets were blowing strong.

Hopefully this info helps. I appreciate any suggestions!

Thank you.

My pool/spa is concrete and 20 years old.

Drop the water level to just under the jets' level. Then put it in spa mode. You should see 4 equal streams. If one of the streams is more of a gush, shut off the pump and look inside the jets. Each jet, assuming they are the most common type, should have a nozzle that looks like a white tube. I suspect one is missing it's tube.

Scott

Sorry Scott,
I didnt read your post, I think you nailed it as well.
Great minds think alike.

Thank you all very much for your response.

Turns out one of the orifaces / nozzles broke off and was laying on the bottom of the spa. Without the resistance, all the water was rushing out of the one jet.

I'm hoping the oriface / nozzle fully came off from the jet, so all I have to do is put a new one on.

Thanks again!

They thread in. "Gently" tapping a flat head screw driver so it's edges bite the inside wall of the remaining piece should allow you to remove the remaining piece.

Scott

Just had the pool and spa remodelled. broke out all old plumbing in spa and replaced with new. Also New DE filter, etc. everything was pressure tested before applying new pebble plaster - (a mess and plenty of debris).
the 4 spa jets are pulling almost no air at all and the water flow seems much weaker than before any construction. The old nozzles looked like tiny starfish that could be aimed and screwed open or closed to change the flow (I think) but the new ones are just open holes big enough for my index finger. I thought that was the problem but contractor said those aren't available anymore, etc. He added a blower motor which barely helped the flow and still only 2 of the 4 are emitting any air. It seems like the jets (behind the nozzles) are likely clogged - right ?
if they even used jets at all...how do I remove and clean them out - or replace if that's the diagnosis ?
Thanks !!

Did you get any pix of the demo work?

Scott