How to find and fix leaks in your pond

One of the most frustrating things pond owners can encounter is a leak. Not only can leaks be a major waste of water, it could also harm your pond’s ecosystem, especially if you have fish. But before you can try to fix a leak, you need to know where it is coming from.

In this guide, we’ll look at some of the ways you can spot a leak, the potential cause, and ultimately how to fix it..

What causes a pond leak?

Water loss is a common issue for ponds. In most cases, this could be down to water splashing out from a waterfall or fountain feature. Or it could be a bigger problem, such as a leak in the pond liner.

Some common causes of water loss can include:

Damage to the pond liner – either due to wear and tear or punctures which can cause water to leak out.
Equipment such as your pond pump or filter – which could be leaking due to damaged pipes.
Evaporation – which can cause water loss during hot or windy weather.
Plants within the pond absorbing the water
Damage to the liner from animals such as dogs, birds and foxes.
Wildlife drinking from the pond – which could lower the water level over time.

It may also depend on the type of pond you have. A natural pond, for example, may have more complex reasons for leaks such as shifting soil or roots growing into the liner. Whereas a concrete pond may be more susceptible to cracks over time.

How to find a leak in your pond

Identifying a leak in your pond can be a frustrating task, as it’s not always clear where the water is coming from. Before you rule out anything, it’s important to eliminate other potential causes. Here are some steps you can take to find a leak in your pond:

Inspect your equipment

There may be damage to your pond pump, filter, or other equipment that is causing water to leak out. Check the current water level before you turn off any pumps or waterfalls in the pond. Once a few hours have passed, check the water level once again.

If the water level has stayed the same, there could be a leak within the plumbing. But if the level has dropped, there could be a leak in your pond liner.

Inspect all the connections on your pond pump and filter to ensure they are secure and not leaking. Some pumps can deteriorate over time and develop cracks or splits, leading to small leaks in the pipework joints. If you notice any leaks within the pump or filter, replace the affected part or system to prevent further water loss.

Another cause could be from blockage in the pond filter, causing water to overflow from the filter box. Check the filter media inside your filter system for any blockages. If the filters are dirty, remove them and rinse them off with a hose to wash away any dirt or algae.

Check the liner for damage

If you notice that your pond water level is dropping, it could cause damage to the pond liner. Before you take action, you should inspect the liner for any cracks, splits or tears.

Start by turning off the pond pump and noting the water level. This will help you determine if the water loss is due to the liner and not a problem with the pipework. If you believe it to be an issue with the liner, carefully skim the surface of the water around the water line to locate the hole.

If there is indeed a leak in the liner, it’ll need to be repaired promptly to prevent your pond from losing any more water. If you have fish, you should rehome them in pond water while repairs are made so they are not harmed.

Check for evaporation

During hot or windy spells it’s common to see a loss of water due to evaporation. This could be a loss of 1-3 inches of water per week depending on size and depth of the pond. To monitor the water level, you can place a marker at the water line and check it regularly.

The bucket test can help to identify if the water loss is due to evaporation or a leak. To do this:

Place a bucket filled with pond water (about two-thirds) next to your pond.
Mark the water level on both the inside of the bucket and in the pond.
Turn off the pump and autofill (if you have one).
Mark the water level on the inside of the bucket.
Turn the pump back on.
Check back after 24 hours to see if there is a difference in water loss between the two.

If both levels have dropped at the same rate, evaporation could most likely be the cause.

You can reduce evaporation by adding some shade to your pond or using a cover net as well as topping up any lost water.

The Dye Method

Another way to find a leak is by using the ‘dye method’ – this involves adding a small amount of food colouring or pond dye to the water and observing where the colour travels. If there is a leak, the dye should be drawn towards it, to help pinpoint the location of the issue.

The leak may be small and difficult to spot, so don’t worry if you think you’ve poured too much dye into the water. The dye will disperse quickly and should not harm any fish or plants in your pond.

How to fix a pond leak

If you find a leak in your pond, it needs to be repaired as soon as possible, otherwise your water levels will continue to drop and could cause potential harm to fish. Once you have identified the source of the leak, you can take steps to repair it.

For damage to the pond liner, you can use:

A repair patch or sealant specifically designed for pond liners to cover the hole or tear.
Pond liner joining tape and adhesive to seal the leak.
Repair sealant and a patch kit for larger tears or holes.

For leaks in the pipework, you may need to replace the section with a new piece of pipe or connector. Once repairs are made, monitor your pond water level closely to ensure that the leak has been completely fixed.

For leaks in the pump or filter system, it may be best to order a replacement part or the entire system.

Preventing future leaks

A leak could happen at any time so it’s important to take steps to help avoid problems in the future. Here are some tips:

Monitor the water level of your pond regularly to catch any leaks early on.
Regularly inspect your pond liner for any signs of damage and repair them promptly.
Avoid placing sharp objects or heavy rocks on the liner that could cause tears or punctures.
Monitor plant growth.
Clean debris regularly to prevent clogs in the filter.
Check the connections and seals of your pump and filter system regularly to ensure they are secure.

We recommend adding a pond net or cover to help protect your pond from debris, animals, and extreme weather conditions that could potentially damage the liner. Check out our seasonal care calendar to keep your pond in top shape all year round.