I have a 20 gallon freshwater fish aquarium and I am having a terrible time with it looking smokey and also there is a lot of algae. I have several fish including auto's and all of my fish are doing very well. I just gave the aquarium a very good cleaning a few days ago and it looked beautiful. Now it looks like I need to clean or suction it again. Please can someone tell me what the problem might be? A reply will be greatly appreciated.