Great article!! I did not read all 23 pages. Just one question. I have a 90 gallon aquarium with discus in it and want to minimize the amount of current in my tank. I am pondering doing just sponges, with a particle filter on an aquaclear powerhead. I have 9 discus in there ranging from 3" to 5" in diameter. I also have 12 hets, and 6 rummy nose, and 4 cory cats. The tank is planted and I do water changes every other day. Was thinking of doing 2 50 gallon sponge filters. A brand named deep blue. New to the market I believe, but they are available at my lfs. What are your thoughts please. I am currently using an aquatop cf500uv to filter the tank, but I want to use if possible solely the sponge filters.