I've had a pool renovation and added new spill over spa. I am not getting a lot of pressure through the returns so contacted someone else to look at it. ( long story, not having the PB back.. he subbed this part out and everything this guy did is Crud, an whole 'nother conversation ) Thank god I took a photo before the gunite, at least that... So new person said that this plumbing isn't correct. That the flex lines should not be sagging like this it interrupts the air water mixture. Also, seems I just have returns there are no jets in them, I am not sure I understand any of this. But he said i can use it like this, but if i want it to work like a real spa with the air water mixture that he can cut in from the outside and replumb it.