I asked this before, but now that I'm SLOWLY getting closer I've got more questions. I haven't made too much progress over the past month, as I hurt my back before it all got started. But Tunnel #1 is about 50% complete and I think I've got the kinks worked out of the digging process. So I'm wondering how I'm going to insulate the exposed drain pipe. The pipe will be about five feet under ground before it enters the filter room and goes into the filter. The filter room is mostly below ground and insulated on the outside with plastic and styrofoam. But it does have a door to the outside and is proably very close to the ambient air temperature. COLD. So my options are: 1) Put a knive valve below ground somewhere near the pond. This is probably the best idea, but servicing could be a PITA. 2) Put an insulated box around the gate valve inside the filter room. 3) Wrap one of those electric heaters around pipe inside the filter room. 4) Put a better door on the filter room. Probably not cost effective. Any thoughts on the least trouble free solution?