i have what i believe is an older Santanna spa. we just noticed that the jet thats by the skimmer box for the filter doesn't flow. inside the skimmer box on the side wall is a valve that can be completly unscrewed like an air venturi. i traced the plumbing from that jet and air intake(if thats what it is). it goes straight down to the ground into some sort of 4 way diverter with the air intake in the top of it. its a rather larger jet compared to the rest so would like to see it work.
on another thought, the other side of the tub has a huge grill with a very areospace looking jet like this
http://spapartsnet.com/Jets/Hydro-Air-Jets

it doesn't seem to seat into the inner jet(just falls out) so alot of the flow kinda gets diverted. i read about getting a peice of lexan cut to fill in the hole and put a differant jet in it. any suggestions as to what i need to do this or can i use any jet i want. i'm assuming that i would just leave the old jet body intact and extend it to the body of a new jet in the lexan?

heres a similiar pic of the 4 way valve i'm talking about, except mine only has 4 screws on the top.

well figured out the large jet operation!LOL! there was a sqaure cover on top of the tub i hung the thermometer from, i thought it was used to introduce fragrances and such. last night i tried to pull it off and it was stuck so i turned it a bit to remove and what do ya know the jet worked! weird looking control for it but jeesh it shuts of the rest of the jets and is super strong.