I've been doing lots of idle reading about various media that you can use in your aquarium filter to help with the Nitrification process. Below I've collected some articles which I found quiet interesting to read:
1) BioMatrix Looped Cord Media,
marketed at the time by BioMatrix vs
material manufactured by the 3M Company of St. Paul, MN. This article compared these two materials and found they performed about the same but the scour pads had a marginally better performance. One of their conclusions "The better performance of the 3M fabric over that of the BioMatrix
system was most likely due to greater surface area."
2) This article tested nylon pot scrubbies as a filter medium. They found it works and also found that slow / trickle filtration is best for removing the most amount of ammonia.
Pot Scrubbies: Surface area/cu.ft.:370
Scour Pad: Surface area/cu.ft.:150-200
3) This article gives a list of media and their surface areas.
4) A comparison of Seachem Matrix vs Eheim Substrat Pro and JBL MicroMec can be found here.