Great community you've got here!
I've read a number of different things about how to determine the size of filter you need.
I've got a 21' AGP, so around ~10k gallons. Given that, I need a flow of ~21gpm. A .5hp pump should easily do the job. I'm just not sure what size filter I need. Based on "sizing your filter to meet your pump", I could get away with as small as 25 sq. ft, I think? There are a variety of sub-100 sq. ft. filters available on Amazon (though, weirdly, almost no .5hp pumps).
But it seems like all the charts I see *start* at 100 sq. ft.
Also, I know it's best to go as big on the filter as you can afford. But ideally we'd like next summer (and maybe this one if things work out) to be our last at this house. So it'd be great to spend as little as possible since we're only looking short-term.
Any advice would be greatly appreciated!