Just went through a pool resurface and upgraded lights to led. The conduit is from the 80's and probably has a pinhole somewhere. Is it necessary to drain the pool to apply the butyl tape? If I do drain the pool is silicone an acceptable sealant for pools? Will the chemicals degrade it over time. I've read about underwater epoxy on the forums. Will that stuff really stick to surfaces underwater. It seems like I could get the silicone farther up the old conduit to seal it up.