the water inlet is not sufficiently open to prevent the backflow of water from the tub into the air inlet application_number US 79744185 A description referring to fig1 and 2 a first preferred embodiment of the present water jet aerator 10 includes a housing 12 having a first internal chamber 14 and a second internal chamber 16 the chambers 14 and 16 are substantially cylindrical and have threaded interior walls the housing 12 has an open front end 18 as shown in fig1 which leads into the second chamber 16 surrounding the front end 18 of the housing 12 is a frontal flange 20 which abuts a wall 22 of a tub or spa as shown in fig2 the housing 12 is clamped to the wall 22 by a bushing 24 which is passed through a hole in the wall 22 the bushing 24 has exterior threading to mate with the threading in the second chamber 16 a flange 26 on the bushing 24 also abuts the wall 22 to clamp the aerator 10 in place preferably an air conduit 28 and a water conduit 30 are joined to the housing 12 the conduits 28 and 30 are respectively connected to air and water supply lines not shown the water conduit 30 feeds into the first chamber 14 through a water inlet 32 in the housing 12 and the air conduit 28 feeds into the second.