We are having (and have had every year) a serious problem with clear water. We have our water tested and have spent enough money trying yo get clear water, we could have purchased a new pool. That being said, we are curious if it is really a chemical problem, or a filtration problem. Currently we have a 1.5 hp pump with a sand filter-~100lbs of sand in filter. Our pool is green. Our ph is 7.2 cya 70 currently, FC <4. We have killed the algae and pool went from green to milky blue. Added this, added that, no change and then back to green. Any advice is welcome and appreciated.