Until you actually starting injecting CO2 via either DIY or Pressurized, the Bio Wheels and the splashing as the water returns to the tank is a good thing. They help return CO2 to atmospheric levels, which keeps the CO2 levels up in a non injected tank. Once you start injecting CO2, this becomes a bad thing since it means that they are helping to gas off the extra CO2 you're trying to add to the tank.
While you could put together a DIY CO2 setup for a 55 gallon tank, you'll probably find that it is one huge headache. You'll need to setup and regularly change out several bottles of CO2 mix (probably six 2 liter or three gallon bottles). Changes in the house temperature and other factors will affect the CO2 output and make it difficult to maintain a steady high level of CO2 in the tank. Further the amount of sugar and yeast that you will go through, would quickly pay for a Pressurized setup without even taking into account the cost of your time. Add in the cost of Excel, and that Pressurized setup will be paid for even sooner.