Hi...just set up a tank for malawi fish in a 48 inch tank got all my filters... rocks etc i put 5 fish in to start with everything was goin great then i added another 5 fish 2 weeks after that i noticed the water as gone cloudy not alot cloudy all water test is fine what am i doing wrong....

First question, did you cycle the tank? Because this is the new setup, I would imagine that what's happening is you haven't got enough bacteria in your biological filter to deal with the amount of waste that is being produced. Basically, if ammonia starts building up in the tank water and there is not enough bacteria in the filtration to deal with it, another type of free swimming bacteria will start building up in the tank water. This is what is causing the cloudiness in the tank water. Firstly you need to do is a water test, ammonia and nitrite, those are the two most important tests to begin with. Also check the nitrate to see what's happening there. If you've got an absolute Zero reading of nitrate, then I very much doubt your tank in cycled properly.

Be careful testing ammonia on cloudy water. Depending on the test you used the results can come back all screwy. The best one to use is Aquarium Pharmaceuticals two bottle ammonia test. Even if the color precipitates to the bottom after five minutes, on this one you can still shake it back up and read the results.