I am a pool and spa technician in Florida and I care for an in ground spa that is 2350 gallons, has 12 jets and 2 therapy pumps. When the therapy jets are on I have water coming out of the air induction pipe. This did not start happening until about 3 or 4 months ago. The type of fixture and jets are SP1434PAKA and SP1434PAKB. Nothing on this spa has changed for years. Can someone please help me understand what is happening?