Hi everyone! I recently bought a new filter for my 70 gallon aquarium in my families dining room and would like to know if I have enough filtration to house 6 or 7 discus. My newest filter is the Cascade 1500 and it's been running pretty smoothly (set it up last week, however it is doing a little whistling near the returning flow which I have to adjust). I also have a marineland penguin bio-wheel 350 and two sponge filters that are made for 60 gallon aquariums. I'm feeling pretty comfortable with my set up right now and don't feel like I need to worry all that much about filtration now. Would this be an adequate amount of filtration? Thanks in advance!