Pump size

I just bought an 18' X 48" AG metal frame pool to replace the same size easy set pool that was damaged in our last hail storm. The old pool has a pump that pumps 2000 gallons/hr and is a 5500 gallon pool. The new pool is a 6300 gallon pool, but the pump that comes with it pumps 1500 gallons/hr. This makes no sense to me at all and I'm considering using the old pump, since it will circulate more water each hour. Am I on the right track here?

I don't think it matters. Your new pump will turn over your water in less than 4 1/2 hours, your old one in 3 1/2 hours. That's pretty darn good! Most people with larger pools and pumps are thrilled with a turnover of 6-8 hours.

I would attempt to determine which ran better and which has the better filtering. Generally, for filtering, slower can work better (especially for sand), but for agitating the pool water, faster can be better. If one filter is clearly better at cleaning the pool, use that.

You can also look at the electrical draw both use. If the new pump is rated significantly lower in either wattage or amperage, it will use less electricity even though it runs longer. If it's about the same, the bigger pump is better.

If you aren't sure, then use the rated voltage and the amperage to find the wattage, with this formula.

Watts = Volts times Amps.

But I suspect it's OK either way.