Here is another combo, also a 2 speed pump, also a Hayward but with a larger sand filter....21" versus the 18" above. This confuses me as before we talked of sand filters as being 200lbs, etc so not sure why it tell the inches rather than lbs of sand? Im assuming I want my sand filter to be the correct size for my pump or do I go by the size of my pool?

http://www.amazon.com/dp/B002HHM020/...P89FGH0U&psc=1