There are three principal types of filter media - mechanical, biological and chemical. All are designed to do a specific job and they can be used in isolation or in combination.

Mechanical filtration

Mechanical filtration traps particles that pass through it and clears the water. Information technology's the about basic form of filtration and the 1 that most people can really run into working as it tin turn muddied water that is full of particles into articulate water.

Lots of dissimilar materials tin can be used in mechanical filtration but the most common are sponges or filter foams, floss, wadding or filter wool. Drum filters are also mechanical filters that pass h2o through a fine, self-cleaning screen mesh. Make clean h2o passes through the drum and clay is left outside information technology, and flushed to waste matter.

Mechanical filter media needs the virtually maintenance as it's at the front end line of filtration. Sponges and filter floss trap more and more than particles until they block upward with dirt, either cut off flow to the rest of the filter or sending water to a bypass. When mechanical filtration is dirty it must exist cleaned or replaced with new, and its the primary reason that we clean our filters.

Biological filtration

Biological filtration provides a home for live, beneficial leaner to colonise. Its bacteria that make fishkeeping possible every bit fish produce waste through their gills yet that waste material volition poison them if information technology'due south non dealt with. In nature, fish waste is either diluted by the sheer size of the lake or done away in rivers and streams.

In a pond, nosotros use bacteria to convert ammonia from fish into nitrite then nitrate. Without these tiny, tireless helpers converting fish waste we wouldn't be able to go along and so many fish in our ponds and they would die from poor water quality.

In that location are lots of different types of biological filter media from big plastic pipes to small plastic chaplet, ceramic shapes to jagged rocks, coarse matting to circles, crosses and sponge. A sponge tin can work both mechanically and biologically and is often the sole form of filter media in very basic filters.

Area is key to effective biological filter media equally it needs millions of tiny pores for the bacteria to stick to and find a dwelling. Mechanical media should e'er be used beforehand to remove dirt particles as they volition clog the tiny holes and smother the bacteria.

The corporeality of surface area varies from media to media with many conflicting views on which one is best. As practiced as whatever bio media is, when you offset purchase and install it its sterile, so takes time to mature and build upwardly that layer of beneficial bacteria.

Lack of bacteria is the number i cause of fish deaths in ponds. To gainsay this seed new filters with bacteria, test water, and build up stocks slowly. Alive leaner need oxygen from flowing water pond filters must e'er be running, 24 hours per day.

If running separate mechanical and biological filtration the mechanical media can be cleaned and exchanged regularly, only the biofilter must always exist mature and uninterrupted. If you throw away your bio-media or wash it under the tap, yous lose the leaner and it's them that are the life support organisation for your fish swimming.

Chemical media

Chemic filtration is less common in pond filters only information technology can be used to do a specific job. Carbon, Zeolite and Phosphate remover are three examples of chemical media and they are added to the filter to soak up impurities similar dyes and odours (carbon,) ammonia (zeolite,) or phosphate.

Pond h2o turns yellow over fourth dimension from algae, fish nutrient and biological filter processes, and so carbon can act equally a final water polisher to give you lot gin clear h2o, but it must exist used in conjunction with mechanical and biological filtration. Zeolite can be used in h2o quality emergencies to remove ammonia from the h2o although information technology shouldn't be used long term equally information technology starves the bacteria of their food source. Phosphate and nitrate removers do exactly that and are most frequently used to help cure algae bug in ponds.

All chemical filter media has a finite life and once information technology's saturated it must be removed and thrown away. Change chemical filter media on a monthly ground.

So which is the best pond filter media?

The all-time filter media is a combination of mechanical media and split up biological media. The mechanical media traps physical waste product and the biological media converts liquid waste. Choose a swimming filter with dissever mechanical and biological media, with room to add together a purse of chemical media if needed.