Good news!!!! , my tilapia are eating like crazy! the water is crystal clear and the fish seem very happy. Thanks for all the good info guys. If and when I can afford to change my filter set-up I will post. I am so glad they are acting normal again. The filter has a chemical haze on the top of it's water. I think the filter took all of the chemical out of the fish tank and broke it down for the most part. Obviously something went right because they are tearing up the food!!!