Help! Water is Clouding mysteriously

[Angelfish898]

Ever since I started my 10gallon my water has been clouding up every week. I am using Tetra Flakes that don't cloud up the water and I only feed them once a day or every other day with a good amount. Each week I have to change half the water. It is like the filter is not working. Also I am using 2 aqueon 10g filters and an undergravel. could it be that my biological filter not set up well? What do I do? How do I fix it? Thanks