Well if it's cloudy, then you got a bacteria bloom. Means there's to many nutrients and not enough beneficial bacteria. I don't know what kind of setup you have, but you need good filtration, reduce your nutrients (food, dead fish, trace elements), and you want to cycle your tank for a bit to build up that beneficial bacteria. It won't harm your fish it just doesn't look very appealing. Make sure your water has adequate aeration. I would run out to a petshop or fish store and pick up some stability or cycle. Follow the directions and you should have a good cycle by the time your halfway done with a bottle. Keep up with a bi weekly water change.