My sump needs more filtration. My local hardware store sells carbon filter pads that are made for ponds. Will they work ok? I was thinking of cutting it to size and putting in my first baffle that goes to the return chamber. It is a 39 gallon sump on a 125 gallon tank with a mag 18 for return. I did add a skimmer but I need a bigger pump for it. The is also chateo in the center section. Pic's included.