happens to my uncle all the time azumi but never to me!
-usually will happen after a water change, NEVER do a full water change only 30-50%.
-you need a good filter that can cope with the amount of fish in your tank n if it can't it will get cloudy!
-also could be algae blooms in the water but that would kinda have a greenish hue to it as far as i no but u could try: http://www.edirectory.co.uk/pf/880/mia/d...id/5166415 - green away, but i doubt that is the problem.
-also aeration in the tank could effect it so get a bubble blower thing, i have bubbles the length of the back of my aquarium on about 2 days a week.

n e of them n e help??