I agree with bama, go larger on the filter (your current one is ~2 sq. ft. which is small for you pool).
One caveat would be that going much larger than ~3 sq. ft. with the filter might mean your current pump won't have a high enough flow rate to backwash properly, though we would need to know more of your plumbing details to determine this.
I did not see the replies until after we purchased. The guy at the store ended up talking us into this one. http://interpools.com/?proId=1335&gid=8712&pstart=1 It's a 22' Cyclone that was on sale. He talked about the problems that this brand had 2 years ago but said they have improved the flange issues etc. and that the 10 year warranty is a good feature for them. The other option that was in stock right now was the 26" pentair Sand Dollar. They have more coming in tomorrow so if you guys tell me we've made a mistake I'm all ears. We were planning on installing it tonight though...because everything is more fun when it's dark, you're tired and squashed into a small shed with mosquitoes swarming.
I asked about a billion times what the downside would be to this filter and he said the brand and that we'd have to backwash more often and said that would mean about once per week.
I am a total researcher and hate making quick decisions on things like this.
As for our water testing. I had them do a sample while we were there and they said the chlorine is at 0.5 and the stabilizer at zero. I know the stabilizer is not at zero since it wasn't last time we went to a pool place for testing and since then we've added quite a bit. Also, no chlorine has been added in 48 hours and it was at 3 at that point, so.... I don't know how to explain any of this . Our calcium is apparently very high which I'm sure is because my other half has been adding granular chlorine. I'm wondering now if this could also be the cause of the chalky water?
Just wanted to thank everyone again for all of the advice while I had my little breakdown. The pool is running better than ever now with the new filter so something went right! The water is also finally clear so I'm thinking that the calcium built up super high and the old filter just couldn't help it out.
Regardless...the new (expensive!) test kit is en route and I'll be back with lots more questions at that point I'm sure.