What size of new filter to get - getting different answers

[johnnyringo]

Any thought on the approximate size of cartridge filter that I need?

[PoolDoc]

Here's Pentair's page for one of their cartridge filters:
http://www.pentairpool.com/pool-owne...filters-28.htm

Click on the "specs" tab, to match a filter to your pool volume and water flow. It looks like the smallest one would be within specs on your pool. But, with cartridge filters, there's no downside that I know of to oversizing them, and you'll be able to go longer between cleaning with an oversized filter.

[johnnyringo]

Thanks!
So the last pool guy I talked to (who was recommended) is proposing a Pentair 520. That sounds massive. Is that just way too big???

[johnnyringo]

Can anyone say if Pentair 520 is way too big for my pool? I have to have a decision by morning and have no clue.

Thanks!!