Just got my pond done last month and I am thoroughly enjoying it! It is a preformed liner, 175 gal, 18" deep with shelves and an "island" offset from the middle that is maybe 6 inches deep. I do not have fish. The main purpose of my pond is plants and small wildlife/birds.

My question is should I try to keep the pond from completely freezing this winter, or let it freeze since I don't need to keep a hole open for fish.

My main concern is the pond liner cracking from the pressure (even though pond liner brand says that it won't crack). I'm in zone 5 in Iowa.

I was thinking of running a low watt deicer OR draining the pond a few inches so that the "island" part sticks up so I can keep a few inches of water in there and run a birdbath deicer for the birds.

Any suggestions will be appreciated!