Installing a pond filter is an essential in keeping your pond water clean for fish and plants to stay healthy. Whether you've chosen a box filter, pressure filter, in-pond unit, or a Koi filter, this guide will explain how to install each type of filter with clear and simple tips.

If you're stuck choosing the right filter for your pond, try reading our help guide here.

How to install a box filter

Box filters are very easy to install and are ideal for ponds where water can be returned by gravity. These pumps are especially useful for clear water returns and simple waterfall setups.

Installation:

The box filter needs to be placed on a stable and level surface near the pond, ideally at the edge. The outlet should be positioned over the pond to allow water to drop back in naturally after being filtered. Connect the pond pump to the inlet of your filter using the appropriate hose size.

If you're planning to include a waterfall, you have two different options:

  • Use a 'T' connector to split the water flow, using hose to direct one to the filter, and the other to the waterfall
  • Place the box behind the waterfall for a natural return of filtered water

It is advised to avoid reducing the outlet pipe diameter, or extending it too far, especially uphill, as this can cause flooding or back-pressure in the system.

How to install a pressurised pond filter

Pressurised filters are easy to keep discreet, so as not to interrupt the view of your pond. You can place them far from the pond, or even bury it up to the lid.

Installation:

First, you need to decide if you would prefer to bury the unit. If you do, you will need to dig a deep enough hole to fit the body, whilst keeping the lid above the ground. If you aren't burying it, place it on a stable and level surface.

Then you will need to:

  1. Run an inlet hose from the pump to the filter
  2. Connect the outlet hose from the filter to return the water to the pond or waterfall
  3. If you are using a UV clarifier, make sure it is connected to a weatherproof power supply

Some models of pressurised filters feature a third outlet for flushing waste. During routine maintenance, you can allow the waste water to flush into your garden or, using a hose, direct it to a drain or flowerbed.

How to install an in-pond filter

In-pond filters are the easiest filter type to install. They are compact units that are placed directly into your pond, preventing obstruction to your view.

Installation: 

  1. Place the unit on a flat, level area of your pond floor
  2. If your pond is not level, make sure the model includes an adjustable head to help with uneven pond floors
  3. Check the filter intact is fully submerged in the water

Tip: To make retrieval easier, you could tie a length of string to the filter. Never pull on the power cable.

If you are using a fountain feature, make sure to adjust the fountain head so it sits just above the surface of the water

How to install an all-in-one pond filter 

All-in-one filters are plug and play systems, ideal for beginners. Combining a pump, filter, and often a UV clarifier makes set-up easy and quick.

Installation:

  1. Lower the unit into the pond, placing it in the centre of your pond, on level ground.
  2. Plug into an outdoor socket and test the unit, making sure the water is flowing and system is working efficiently.

Tip: To easily lower and raise the filter, use a length of string tied to the unit. Never pull on the power cable. 

How to install a Koi pond filter

As Koi are messy fish that produce a lot of waste, their filtration needs to be powerful. Most Koi filters are either pressurised drum filters or multi-chamber box filters, so installation may be different depending on which model you choose.

Considerations for installation

  • Position gravity-fed Koi filters above the pond water level
  • Use a high-capacity pump that is compatible with your filter's flow rate
  • Set up a waste flush point with easy access for regular maintenance

Tip: You will also want to pair the filter with a UV clarifier and regularly test water parameters due to Koi's sensitivity to water quality.

For more information about Koi filters, check out our help guide here.

Correct installation is key

No matter which pond filter you are using, installing it properly is the most important step to clearer water, a healthier aquatic environment, and overall long term success.