The filter I have now came with the 29 gallon aquarium from Walmart. It's part of the Regent series. I hear that there are Penguin 170 replacement parts for my filter that will allow it to have a biowheel. I found some parts that will let me have a biowheel, but it costs $16.46 shipped. I can get the Penguin Bio-wheel 350 for $21 shipped, so should I go ahead and make that purchase, or is it overkill for my aquarium? Now, that I typed this all out, I'm feeling that I should definitely get the Penguin 350...