Ok it's been less than a month when I purchased this 55 gal. set up on craiglist. It came with an undergravel filter(which I disposed of quickly) and a whisper 60. So I get everything set up and running. After a week I decided to add a couple fish. My son chose a three inch oscar, a firemouth and two small silver dollar fish. A couple days had past and I got the cloudy water thing going. So I did some research and figured that I need better filtration. so I purchased a Eheim 2215 and within a day most of the cloudiness was gone. Now after three weeks of this running my water is still somewhat cloudy. Oh and yes i have been doing weekly 15% water changes. Is this because the tank is still new and cycling or do I need to add the whisper back on the tank along with the Eheim. Other than that fish are fine. I only been feeding once a day also. Any ideas and suggestions would be greatful.