Need some input here. Due to my raised spa draining back into the pool each night, I'm fairly certain the check valve on the spa fill side is no longer doing its job. If I shut off the Jandy valve to the spa after the pump is off, it does not flow back into the pool, so I'm thinking the check valve is bad. My question is, do you think that I will have enough pvc left after removing the old one? I'll have about 3/4 of an inch left.