hmm, boy I get more confused the more I read, lol. All that flow rate, amps, head pressure, etc is getting over my head. Sounds like greek most the time. I understand a little here & there.

Im not happy with my 1.5hp because it is so powerful it appears to just blow the water thru the sand filter without actually filtering anything. Not to mention, being old , loud and using lots of electricity. Now the lid is broken so its leaking, hence Im replacing it. Granted I never determined if my filtering problem was a too big pump or a faulty sand filter so that makes me hesitant to know for sure what I need. But it SEEMS from reading on here that a smaller pump would be better not to mention cheaper to operate.

However, if I went back with a 1.5 hp 2 SPEED then I do have the option of running it on low so maybe that is the best of both worlds for me. I can run it on high for quick circulation or to vacuum but keep it on low to save energy and filter better. Before I only ran the 1.5hp for 3 hrs per day which was basically just to circulate the water, it didn't appear to filter anything. As reading in my earlier post, we controlled the filtering by using skimmer socks and then letting the worst debris settle and vacuum using the bucket method. Vacuuming using the pump seemed to scatter the small particles but was nice for big debris like leaves.

Ok, so this combo here might be the best of both worlds for me:

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

However I have one concern: IS THAT FILTER BIG ENOUGH FOR THAT PUMP? I think 21" might be 150lbs of sand? Some people say the combos are always sized with a too big pump. Others say its easier to use properly matched equipment made for ea other.