I just back filled my DIY pool 2/3 and the pool is full and it just dawned on me that I ran my conduit horizontally along the pool wall with the plumbing at 30" below ground ramping up to ground level. This exposes about 60 feet of water filled conduit to freezing. Has anyone ever successfully blown out a light line and found a plug that would seal around the light cord and into the conduit hole in the niche or should I dig the up and bring the conduit straight up to the surface then to the transformer so when the water freezes it can expand upward? I really could use some input before I pour concrete. Thanks.