Ponds 101

Chapter 6

Circulatory and/or Filtration System

Of course, there are lots of ponds out there with no circulatory system or filtration, but let’s talk about typical setups here, at least to start with. There are three parts to the typical pond circulatory/filtration system: pump, skimmer and biological filter. The heart of the system is the Pump, circulating water inside the pond or up to the top of a waterfall or stream, and coming in a couple of flavors.

The next component commonly installed is the Skimmer, which skims and collects floating debris before it can clog the pump or settle to the bottom, acting as a large, easily cleaned pre-filter. External Pumps may be connected to a skimmer, but most ponds built these days use skimmers that are large enough for submersible pumps to sit inside of. Although certainly optional, most ponds these days use skimmers for three very good reasons: the pump is easy to access for cleaning and maintenance; the skimmer filters the water and keeps the pump out of the muck so it usually lasts longer and, of course, skimmers also skim, reducing the debris that collects in the pond.

The water from the pump in the skimmer is usually pumped into the third component of the filtration system, most commonly an Upflow Biological Filter. The water enters at the bottom of this type of filter and flows upwards through filter media, overflowing out the top (hence the name), so it’s often located at the headwaters of the stream or falls. Water leaving a properly functioning Biological Filter is screened of fine particles, purified of toxic chemicals such as ammonia and well-aerated by the stream or falls before returning to the pond.

These three components – Pump, Skimmer and Biological Filter – should be matched for best efficiency. Most manufacturers design matching filtration products by pond volume; for example, Atlantic Water Gardens components are typically paired and sized to turn and filter the entire volume of the pond at least once per hour.

Basic Pond Circulation

Pond Circulation