Its ok CTC, we all have this problem at sometime when we begin getting into the hobby and actually set up your first tank.
Since you are not overfeeding and the filters are clean then i think it might actually be the tap water you are using, it sounds a reasonable bet anyway.
I would suggest going down to your LFS and buying a product called AccuClear, it works within 24 hours and makes the water clear.
If you dont want to go down the chemical route then id say just leave the tank to mature, my oscar tank when first set up was horridly cloudy and just would not clear at all, now the tank has matured its clear as glass
