Thats interesting. I have the AR510 as well. My filter is set up with noodles on the bottom, then the black pads then the white stuff with carbon inside. Actually I took the white sponge out at the moment because I find if you dont change it every 3-4 weeks you get these particals that float on the top. I have two filters running in this tank because I found the built in filter useless. I only has 9 guppys and 4 platys in this tank.