[jyl]

I second LeRoux. The water shouldn't be cloudy if you have a good filter setup, and must not be cloudy if you want the fish to be healthy.

Don't overfeed. 15 minutes after feeding, there should be hardly any food visible - the fish should have eaten it all.

Many freshwater aquariums include a bottom-feeder fish, who forages on food that has fallen to the bottom as well as algae that is trying to build up. The most common ones are called "pleicostomos" or something like that.

My most successful aquarium included an undergravel filter. The gravel sits on a raised, perforated floor. Water is drawn downward, through the gravel, through the perforations, under the raised floor, into the filter, and then pumped back into the tank. Does a great job of keeping crud out of the water.

With that setup, plus a regular filter (the kind that hangs over the edge of the tank), I never needed to regularly add chemicals to the water, and to be honest I seldom did partial water changes.

Post a pic of your fish and tank!