I love the idea that this filter has an ultraviolet light included, as UV lights have proven to be useful tools in keeping our past pond more clear. Plus, this filter can be placed just on the other side of our waste-high retaining wall, just outside of our walk-out basement door. Hopefully this will make maintenance much easier. HOWEVER, now I am worrying about freeze damage to this unit, whose top will be completely out of the ground. We live in southern Ohio (not too far from Dayton, Ohio), so we do occasionally see sub-zero weather...sometimes for a week or more at a time. The 250-acre lake we live on often freezes over completely, sometimes a foot thick or more. Our previous pond survived all that...but what about this expensive new filter? Any advice?