I opened my pool up today, and all went find except for a small leak at the PVC junction where the pipe leaves the heat pump. I'm thinking that the ground settled, and there's minimal piping before it goes into the ground which leaves not much to flex and account for any movement. I loosened the collar and could see that there's a gap at the bottom where the two pipes mate up where the gasket is. If it tilt the heat pump back ever so slightly then the leak stops. I could shim the heat pump up with a few small stones, but then I worry about the weight of the heat pump being concentrated to one small point where the pebble is. Any suggestions how to correctly fix this?