Bio-wheels are solely for growing the bacteria for the
nitrogen cycle.They don't do anything else. A regular filter based system is just as good as long as you're not constantly throwing away the filter media (where the bacteria grows). The bio-wheels are supposed to grow the bacteria and the bacteria stays on the wheel,so you can change the filter media without harming the bacteria colony.(and get you to buy more filters that you don't need). I would just wash off the old filter media and re-use it over and over again.It's a nice pitch to get customers to buy it,but is useless and unnecessary in my opinion.