I am going to try a uv light one more time this year. I believe the filter has started a bacteria colony otherwise, there would be no change in the water. I still need to add some media to colonize the bacteria. I had an old pond filter. Had sponges as a pre filter and had round rubber balls in the bottom that i supposed was in there for bacteria to live. I put the balls in the bottom of the 55g drum. But thanks. I did not think of the rid stuff. I will read up on that stuff and give it a try.