Which filter should I install in my pond?

A small pond without fish can be kept beautiful without filtration, using only a pump that recirculates the water and planting plants that oxygenate it. However if you want to incorporate fish, if the pond receives direct sunlight for more than 6 hours a day or if you simply want to make sure that the water is always kept clean, crystal clear and free of algae, you will want to install some form of extra filtration.

Remember that in all cases it is best to manually remove large debris from the pond. If you do not do this, it will be trapped in the filter and may clog it up and reduce its performance.

Here we will give you a list of tips so that you can choose the filter that best suits your needs:

-Pump volume: look for a filter capable of circulating at least half the volume of the pond per hour. If you have a lot of fish or intense sunlight, increase this capacity to 1 or 2 times per hour the total volume of water. If in doubt, choose one with a larger capacity.

-Internal or external: internal or submersible filters are easier to install and do not need to be hidden, but are indicated only for small to medium size aquariums. External filters are much easier to clean. Some come with a built-in waterfall, but otherwise you must attach it to a fountain or make a waterfall that oxygenates the water and also hides the appliance.

-Water intake: the filter can take water from the pond from the surface or from the bottom. In large ponds it is advisable to use both outlets at the same time.

  • Skimmer: the system is the same as used in swimming pools. A chimney collects the water from the surface and feeds it to the filter. It is an excellent way to get rid of both the waste floating in the water, such as leaves and dust, and the dissolved organic compounds and prevent them from reaching the filter directly.
  • From the bottom: this intake collects the large debris that has been deposited at the bottom, such as decomposing material and remains of fecal matter or fish food. It also creates a water current that carries the oxygen to the deepest levels and prevents dead spaces without circulation.

-UV sterilization or clarification: they use a UV light to remove microscopic algae and harmful bacteria from the water. This helps to keep the water crystal clear and the fish healthy. Sterilizers are more powerful. Some external filters incorporate a UV light, but they can also be installed separately, always after filtration because they work much better if the water is free of debris.

-Water outlet: once the water has been cleaned it is returned to the pond. It is ideal to do this in the form of a waterfall, spout or fountain, which in addition to being beautiful and emitting a soothing sound, help oxygenate and circulate the water.

For any filter to work at its maximum capacity, remember to clean it periodically following the manufacturer’s instructions and taking into account the load of waste in the pond.