Obviously it's always best to try to save until you can afford to purchase the pool outright.

However, if you are going to finance it, do it as a home equity loan. This will allow you to deduct the interest that you pay on the loan from your taxable income, saving you money on your taxes. You won't be able to write off the interest on the financing with a finance company like GE Capital (Double check this with your tax advisor, I could be wrong).

We took out a home equity credit line to do our pool, but the processing was slow, and we started the process a little late. We ended up paying cash for our pool since we had enough (barely) to cover the payments as they came due. The home equity credit line was never used and closed a year later when we locked into a 5% 15 year fixed mortgage.

Good luck