An Overview of External and Submersible Pond Filters
Author: Terry Newhaven
When shopping for pond supplies one will see a wide selection of filters for pond filtration. There are many different brands, but there are typically two types, a submersible and an external pond filter. There are mechanical filters that filter dirt and algae and biological filters that break down waste in the pond water. Generally, smaller ponds use submersible pumps with built-in filters, but large ponds need much larger equipment to deal with the quantity of water in the pond.
Garden ponds typically use submersible filters for pond filtration systems. Submersible filters are enclosed in the pond pump housing and sit inside the pond; they are usually used with fountains. The simplest type of submersible filter has a screen or foam that fits on the inlet side of the pump. When water is drawn into the filter, the screen prevents algae and debris from flowing into the pump's mechanism. These screens get dirty rather quickly and require regular cleaning.
Submersible filters are independent devices that return water through decorative fountains, making them a pleasing addition to the pond. The fountain attachment usually hides the electrical cord making it a nice addition to the submersible pond filter. The drawbacks of submersible filters are commonly maintenance ones. When performing routine maintenance, the filter has to be pulled up from the bottom of the pond, which makes this an unreasonable pond filtration choice for use in a bigger pond.
External filters come in a wide selection of sizes and shapes. They will sit outside the pond, with water piped to and from the pond. External filters are more complex, but provide more flexibility when it comes to pond filtration systems. An external pond filter is positioned outside the pond and comes in several varieties of filters including gravity flow, pressurized and waterfall. This style of filter is generally used with larger ponds or ponds with a large fish load where high flow rates are necessary.
The main drawback to external pond filtration is size and difficulty to add to a small pond. External filters are more useful than the submersible style of pond filter. They can be concealed from view, allowing the natural look most pond owners take pleasure in. They can be accessed more easily for regular maintenance, so it can be performed on a regular basis. External filters should be used for all but the smallest of ponds.
Both external and submersible filters can have a place in the pond. Submersible filters work well for smaller ponds. They are easy to work with. They are a valuable addition even to larger ponds with external filters. They can have decorative appeal as a fountain and can be used as an extra mechanical or chemical filtration. They are efficient, and give the best functionality of the two. They can be effortlessly plumbed into waterfalls and streams, and hidden from sight. If used in combination with an overflow mechanism, an external pond filter offers an exclusive, natural setting that a submersible filter simply cannot