last week after few days of hearing this wooshing sound from the chlorinator , i decided to remove it from the line and i found a white plastic cap about 1" in diameter stuck in the orfice ,i removed it and put the chlorinator back inline the noise was gone and the water pressure from the jets in the pool were increased. I have Fibglass 17500 gal. Inground pool and a sand filter made by Cooper industries. more than 10 calls to The manufacturer and e amils were not returens or answred can anyone tell me where this white plastic cap could have came from ?? i do not see any sand in the pool ( noticable ) amount anyway so i thought it might be from the Laterals . T :?: he filter pressure is at 11 psi steady. Thanx