I live in zone 5 also (lma,Ohio). My pond is 3 1/2 feet deep and I had
no problem with fish wintering over all are ok.

I'm in Dayton, Ohio! I doubt I would go 3.5 feet deep, though....I was
thinking more along the lines of 2 feet. (I know it's minimum depth, but it's
all the liner I can afford.)

I have another thought process for my pond....a local business offers a
do-it-yourself package for $929.00. Included a

15X18 liner (45mil EPDM)
5X6 waterfall liner
12X18 Underliner
Supreme 1200gph pump
25' of spiral flex tubing
Pre-filter box
Kiss 1500R bio-filter/waterfall

Now, having looked at each piece through other sources, I can get everything
for $580. I know I'm talking an addition $500 over my original ideas, but I'm
wondering if it would be worth the extra money to do things "better" the first
time.

Also, what can anyone tell me about Xavan liners? I found a website that sells
a 19X13 for $181.00. (A 15X18 45mil EPDM goes for $175 on ebay.)

Thanks and sorry for the change in direction, but I really don't want to get
stuck with something that I'll later regret.

Thanks!

Michelle