Looking INSIDE Filter Media for Aquariums and Ponds
Using a microscope to take a look at the internal structure of some common types of filter media. Please click 'show more' for all information on media, time stamps and worldwide links (where available).
Microscope used: http://geni.us/IyFI0m4
Good biological filter media needs to be receptive to bacteria, have a varied internal structure and last for a very long time if it is to support aerobic and anaerobic bacteria and have a chance of providing full cycle filtration (reduction in nitrate).
It generally falls into 4 categories (for static filters):
1 - PLASTIC- avoid for a static filter as the surface area is so low. Poor receptiveness to bacteria.
2 - NATURAL ROCK - can vary wildly in usefulness and may raise pH (white pumice). Varied receptiveness to bacteria but generally good.
3 - CERAMIC - made from clay dust. Quality of structure and hardness can be very varied depending on type. Relatively receptive to bacteria even on/in poor quality media.
4 - SINTERED G