JETS BLOWING WEAK

[Buf Montana]

I have a large, in-ground fiberglass hot tub in the Chicago area. Everything was working fine last winter, then I had a guy close it for Jan-March then same guy reopened it in mid-April and the jets have been blowing weak (maybe 50%) since then. He thought it was the jet inserts, so I replaced them with same exact jets. That didn’t make a difference so that guy abandoned me, then the next guy had the jet pump (2 HP Pentair) totally rebuilt. That didn’t make a difference, either, so now I suspect there must be some kind of obstruction in the pipes. None of the other pool companies seem interested, so I called a plumber and he brought his smallest scope but it was too big to even make it through the first 90 degree turn. Any suggestions? I also have an air blower that’s in-line with the jet pipes. It will blow air through the jets when the jet pump is not on but once you turn the jet pump on no air comes out the jets, which leads me to believe there is an obstruction somewhere beyond where the air blower pipe meets the main jet pipe and it’s causing back pressure that the air blower can’t overcome. Just a theory, but I don’t what else could be causing this. Any advice would be greatly appreciated.
Thanks

 

[1poolman1]

I have a large, in-ground fiberglass hot tub in the Chicago area. Everything was working fine last winter, then I had a guy close it for Jan-March then same guy reopened it in mid-April and the jets have been blowing weak (maybe 50%) since then. He thought it was the jet inserts, so I replaced them with same exact jets. That didn’t make a difference so that guy abandoned me, then the next guy had the jet pump (2 HP Pentair) totally rebuilt. That didn’t make a difference, either, so now I suspect there must be some kind of obstruction in the pipes. None of the other pool companies seem interested, so I called a plumber and he brought his smallest scope but it was too big to even make it through the first 90 degree turn. Any suggestions? I also have an air blower that’s in-line with the jet pipes. It will blow air through the jets when the jet pump is not on but once you turn the jet pump on no air comes out the jets, which leads me to believe there is an obstruction somewhere beyond where the air blower pipe meets the main jet pipe and it’s causing back pressure that the air blower can’t overcome. Just a theory, but I don’t what else could be causing this. Any advice would be greatly appreciated.
Thanks

Dirty filter is first thing to consider.

 

[Buf Montana]

Jet system is separate from filter/heat system. There’s a separate 1.5 HP pump for the filter/heat system. No filter for the jet system. Just 2 plastic grates on the jet returns on the wall just above the floor of the tub.