How do I get my pool clean?

It has been a week since we opened it and it is no longer that dark, nasty green. Now it is a light green, but it is still so cloudy that we can't even see the bottom of the shallow end (only 3.5ft)! We have put all kinds of shock, algaecide, and Ph increaser in it, but all the chemicals just seem to create a layer of foam on top of the pool. We have been vacuuming, backwashing, and emptying both filters (one in the skimmer and one in near the pump, presumably to catch what is vacuumed up) regularly. Please help us!