What purpose do bio-wheels/balls serve in fish tanks?

Question

I just bought a new fish tank and there are bio-balls that came with it. The last tank I had there was a bio-wheel. What purpose do they serve?

Answer 1

They provide an area for the nitrifying bacterial colonies to develop and thrive. These bacteria are what break down the ammonia produced by fish into less toxic nitrates; so the more of these bacteria you have, the better, and biowheels and bio-balls simply provide an area that is conducive to the bacteria's development. They aren't necessary, because the bacteria will thrive in other areas of your tank (filter sponge, gravel), but they are a definite boost.

Answer 2

I agree with 3 of the 4 posters. Just let me add that in using bio-wheels and balls, its more surface area for the bacteria. Although I use ceramic rings instead of bioballs, its the extra surface area that is effective. The biowheel is a bit different. It has extra surface area with the pleats, but its actually the wheel never being totally submerged in water, and it gets more oxygen, which in turn promotes better benifical bacteria growth and sustainment.

Answer 3

I'll be the third to say, you don't need to clean bio-wheels, they should never need cleaning/replaceing unless they become damaged.

Answer 4

Those wheels collect organic material - fish poop, for want of a better word - as the filter cycles. You have to take them out of the system periodically and rinse them thoroughly. I suggest you do that whenever you change filter pads in your system.