I am installing a semi above-ground Radiant Metric and after installing the liner and filling half-way with water, noticed that there was water behind the liner about half-way up the walls. I have since pumped the water out, fixed my foam coves and am now draining the water inside the liner in order to re-attach it to the walls. I have dug this pool about 3 feet into the ground, which is clay. My question is, should I put some sort of drain tile on the bottom (once the liner is empty) or would a french drain at the surface be adequate. I'm not sure how I would do anything at the bottom of the wall since I have already backfilled all around the pool walls. Thanks for any comments.