I'd take it back. Even if you fix it so it holds water this summer, a winter of freezing & thawing will probably make it recrack, but bigger.

Naw don't take it back. There is a product that works extremely well I just can't remember the name. I think Hydro-Leak or Hydro-Stop or something like it. Ask at the hardware store. I repaired a birdbath that cracked almost entirely in half about 10 years ago. It is still fine. It has been left outside most of those years, so the heat and freezing did not affect it. The product is like concrete mix. Put a little in a tossable bucket, add water and "putty" in on. very easy.

Thanks citytransplant, I really can't take it back due to the weight.

I will take a look at that product.

Chris

I have another idea. I lined our free-form pond out of roofing rubber.......so find a local roofer and see what it would cost for a piece to line your base.
I live in No. Iowa, and it has lasted over four winters!!!!!
Flexible and easy to clean!
Julie