How to filter dirt out of water?

We have our pool up and the water is green, but it is dirt. I took the test and the FAC, pH and alkalinity levels are all where they should be. The water is just dirty, and even though we have shocked the pool and use chlorine regularly, the water is not clearing. The filter is working fine too. I have heard of the Slimebag and it looks great but I have no idea where we could get one and we can't get it online (I am a kid and my parents don't like buying internet stuff) Is there a way I can make a homemade version that filters dirt but lets water pass through? A semipermeable membrane if I remember biology correctly.