A couple of years ago my PVC conduit running to the deep end light must have frozen and cracked creating a slow leak. I "fixed" it by putting a small layer of epoxy around the area where the wires came out of of the cove. This was fine until last year when I needed to replace the light fixture. So, I chipped out the epoxy (fairly easy job), replaced the light fixture and reloaded it with a little more epoxy. Unfortunately this doesn't seem to be doing the trick and winter water level has returned to the level of the light fixture. I understand that there is a rubber stopper that can be used instead of the epoxy?? but the hole is fairly rough (I think gunnite got blown over it) so I'm not confident that rubber will form around the somewhat irregular shape of the hole. Suggestions? Is there something better than epoxy?