Perfect size filter for my pool?

[meganv]

I am looking to buy a used filter to replace my currently leaking pentair 150. I found a used pentair 100, but wanted advice on the size.

How do you figure out the correct sq. ft. filter size for your pool?

Thanks!

 

[jblizzle]

There is a table from Mark that we use as a guideline.

For your 5100 gallon pool, the minimum recommendations would be:
76 sqft cartridge
13" diameter sand
14 sqft DE

But bigger is usually better especially for cartridges. Likely the 100 should be fine, although you will likely be moving more water through it than would be spec'ed for a commercial application (which is only 38 GPM) with your 1.5 HP pump. Although residential spec is 100 GPM and you will certainly be under that.