does any one know adout carbon paper i have a px4 rena canester has 4 trays did not use carbon in the 4th one put bio balls in stead have a power head went home depot got a carbon paper cartridge for a ge water filtration system pluged the bottom hole suction from power head keeps it on my thinking is if you are going to run a extra pump you might as well filter it to besides it is aneather place for bacteria to grow 8 dollors for 2 should be good for a couple of months anyway dont know if carbon paper is as good as carbon still good filter anyway just wonder anyone thinks

I can't think that carbon paper would be nearly as good as regular carbon.

I use the carbon that looks like little cylinders.