Hi Dena, Let me try again.

On my last pool I used 1 1/2" styrafoam on the bottom. I used a lot of the smaller bits and pieces and filled in around the outer edges real good and then duck taped over that. I did not use a pool cove. All of the metal parts were well coverd and my tape job gave it a very small wedge shape. It worked out great.

If you use sand intead of styrafoam you would definately give it a nice big sand cove and foot pack it down good. In my experience with preformed pool cove it is perfect for pools installed on concrete or similar hard surface. I don't like installing them with a dirt base.

You would have to do some comparison shopping. The price of styrafoam or sand and plastic.

The wall foam is another expense but I have been told it is good insulation. If you are planning to heat the pool you may consider it.

Hope this helps a little more, Dennis