Most waterfall biological filter boxes have a large space intentionally left open to be filled with a biological media. The beneficial bacteria colonize on and in this filter media, cleaning the water that passes through it. A good biological filter media has a high surface area for the bacteria to colonize on, doesn't deform under pressure or over time reducing the space for bacteria to colonize or water to flow through, and provides excellent flow of water, to keep the bacteria supplied with oxygen and nutrients.
Ponds with inadequate filter systems tend to require "disruptive cleaning". The process or the frequency of cleaning disrupts the ponds stability. Some filters use a lot of water to clean them properly. Big water changes adversely affect the pond micro-ecology and the fish themselves. Some filters require aggressive or frequent cleaning. This disrupts the stability of bacteria populations. There is no one perfect filter media. Each media will also require certain filter tank accommodations in order to work properly.
Matala® is a cutting edge filter media that was specifically designed for use in aquaculture and Koi keeping and it works great both as a mechanical and biological media. As a mechanical media, it collects debris more efficiently and prevents clogging. The solid fibers resist sludge build-up and are a snap to clean. As a biological media, it provides a tremendous amount of surface area. Matala is slightly buoyant and will not sink to the bottom of your filter. Matala is made of a Thermopoly Propylene compound that is nontoxic to the environment.
Matala® is available in four densities: Black (low), Green (medium), Blue (high), Gray (extra high). The various densities can be used in sequence or separately for unique filtration requirements. This is one of the greatest characteristics which Matala® has to offer. No other media on the market can perform this step-wise filtration.
Your biological filter media should only be cleaned when you do a whole pond clean out, like in the Spring.
For pre-cut replacement filters for all Aquascape™, Atlantic™ and PondBuilder™, please see Skimmer Accessories & Parts and Spillway & Waterfall Box Accessories & Parts.