When maintaining a water garden or any kind of outdoor pond, filtration is essential to the health and well-being of the fish and plants that reside within, so whether you're installing a retail canister filtration system unit or building a do-it-yourself, homemade bucket filter, it’s important to decide which pond filter material is best for your specific project.
Many factors come into play when choosing filter material or filter media for an outdoor pond. Size and volume of pond capacity, size and quantity of the fish that are being kept, as well as the placement of the filters and types of filters being used in the habitat all come into play when choosing pond filter material.
Filter material comes in many different sizes and shapes, but the important thing to keep in mind is how coarse or fine the material should be to clean the water. Mechanical and biological filters offer the use of filter pads which are sold either pre-cut or in rolls of bulk material that can be trimmed to fit your system. These are fine filtration options, which have a smaller surface for the water to pass through and will clean smaller particles and wastes. Coarse filtration options, such as bio-rings, gravel or volcanic rock offer a larger surface for benign bacteria to reside upon and, in turn, rid the water of larger waste deposits and toxins.
There are pros and cons to both types of material: where one type may not clean as thoroughly–coarse materials–the other may get clogged easier and need to be cleaned more often. The choice for the consumer is best made after careful analysis of the size of the pond the filter is going to be expected to maintain.