I purchased a 24 x 52 Intex pool the filter that came with the pool I believe is way too small for the pool. Our pool is always very cloudy and I have to change filter every other day and it is coated with this white , chalky texture. I have taken our water to be tested at a pool store and our chemicals are correct. I have been re-searching getting a sand filter. If recommended what size do I need for the Intex 12,000 gallon pool ?