okay i have a 12 inch oscar in my tank and its by itself in a 55 gallon tank and the water is alwayscloudy like every 5 days. Igot the water checked out but its fine what do i do.

"water is fine" is not a good indicator.
you should be able to know the ff:
ammonia?
nitrite?
nitrate?
pH?
temperature?

another factor of cloudiness:- cleaning the filter
media in tap water or total replacement of the media
whenever you do water change.

or a bacterial bloom......pleas post your water parameters for us to advise further thanks........