The most likely reason for cloudy water is that the filter is not yet mature. It takes several weeks from when the first fish are added for your filter to be colonized by sufficient bacteria to breakdown the waste they produce. If your fish are lethargic or hanging at the water surface, chances are there is a high ammonia & or nitrite level. This is poisonous to your fish. Although the only way to be sure is checking it with a readily available test kit. The cloudiness can be reduced by adding Seachem Clarity, although this will not improve the water quality for your fish.
Read about new tank syndrome.