Hey. I have a 46gallon and im using an aqua-clear filtration system and I love it. Now, i've notice with using one filter, it gets dirty rather quickly. So today, I did a 30% water change and cleaned out the filter, and put another one on top of it. SO I have 2 filters in place. Im debating on putting a carbon back in there. I honestly cant tell the difference between having a carbon and not having a carbon. What do u guys think?