I am adding solar to my pool/spa system. I have a Jandy Aqualink controller. Jandy mentions a 3702 sensor that is used with solar installations. Jandy also has a sensor that is #7790. I know that some of the Jandy numbers only indicate different length on these sensors, but I get differing views on whether these two are interchangable. Jandy says that they are, a pool supplier says not. I am more inclined to believe the pool supplier. Does anyone have first hand experience with this?