There's your problem, often bubblers will create micro bubbles and really make your tank water look bad. Also, I used to have the aqueon 55/75 before I got my canister and I have found that it is better if you just add your own combination of carbon filter floss and other bio media as it is not only cheaper than the cartridges but also more efficient at filtering. Uv
sterilizers are worth it when you get your tank setup though, really puts a polish on your water. Google the mean green killing machine uv
sterilizer as it is the one that I have and works like a charm. Hope this helps!