Pond loses water: water loss

A nicely landscaped pond is a decorative eye-catcher in the garden, but only if it is well filled and the foil used cannot be seen. If the water level drops rapidly, a pond quickly loses its attractiveness. You should definitely do something about that. Fortunately, a hole in the pond is not always responsible, there are numerous other reasons for a sinking water level.

Water level

How far can the water level drop?

Some evaporation is completely normal in summer. If the water level drops by a maximum of two to three centimeters, then simply top up the missing water. There is no need to worry. Have fish in yours garden pond, then make sure that the fresh water has about the same temperature as the water in the pond. In this way you avoid a temperature shock in the animals, which in the worst case could be fatal.

Water loss

Why is my garden pond losing too much water?

The reasons for water loss vary depending on the time of year. In the summer, excessive evaporation could be the trigger. This is caused by extreme heat, but also by very dense bank vegetation. If you notice an extremely low water level in late summer or autumn, then check how much your aquatic and bank plants have grown.

If you have only recently created your garden pond, then perhaps a design flaw that triggers the so-called capillary effect is the reason for the low water level. A broken or leaky filter system can also lead to a low water level, as can a hole in the pond liner.

Capillary effect

What is the capillary effect?

If you have covered the edges of the pond liner with soil or if the liner is not laid high enough, this soil will suck moisture out of your pond like a sponge and the water level will sink. A relatively sure indication of this capillary effect is a swampy bank area. Incidentally, the capillary effect also comes into play in winter, but this is usually only noticeable in spring, when the ice on the garden pond has thawed.

Get to the bottom of the water loss step by step:

• unusually low water level
• Check bank planting and thin out if necessary
• Rule out construction errors
• possibly install a capillary barrier
• Check the filter system for leaky hoses
• possibly repair
• Check pond liner for holes
• Glue the foil

Holes in pond liner

How do I find holes in the foil?

Depending on the size of your pond, finding what may be a small leak can take a long time, especially if the leak is relatively deep. It is best to first fill your pond with water to the brim. Now mark the current water level on the pond liner every day. Initially, the level will probably drop quite quickly, but over time it will only drop slowly or not at all.

The responsible hole through which your garden pond loses water must be at this height. Thoroughly clean the area in question. Perhaps you will discover the leak if it is big enough. If not, then feel this area thoroughly and see if anything is pushing through the film.

Common reasons for holes in the foil:

• sharp-edged stones
• old shards of glass or pottery
• Plant rhizomes, for example from bamboo
• Wrinkles in the foil

Repair

How can I repair my garden pond?

Before you can mend any holes in the film, you must first dry this area out. So let as much water out of your garden pond that you can work in the dry and the leak can be masked over a large area. Special repair kits for garden ponds can be found in specialist shops. Before buying such a kit, make sure of what type of liner you used to build your pond.

You may have to relocate the fish and / or aquatic plants in the garden pond during the repair. So you have enough space for the necessary work. Depending on the film used, this work is more or less time-consuming. In any case, remove the cause of the leak, otherwise your garden pond will leak again in a short time. After the repair, wait at least 24 hours before refilling the pond with fresh water.

Adhere

Gluing PVC film

You can mend PVC film with a waterproof PVC adhesive. Before doing this, however, the film should be thoroughly cleaned. Generously cut out the required patch from any existing or new PVC film. Coat the surfaces that are to be glued together with the special PVC adhesive and press the surfaces firmly together. You can easily remove any trapped air bubbles with a small roller or a wallpaper roller.

PUR liquid pond liner is a means for particularly easy patching or areas that are difficult to access. However, it is not the cheapest method. You should apply at least three layers of this liquid film so that your pond does not leak again in a very short time and lose water again. Let the individual layers dry well before you apply the next layer of the liquid foil, this will make the repaired area more stable and durable.

PVC film is cheaper to buy, but unfortunately does not last as long as EPDM film. If it is already quite old, then it may have become a bit brittle. If more frequent repairs are required within a short period of time due to water loss, then you may consider a complete replacement.

Mending

Repair EPDM foil

The EPDM film must also be thoroughly cleaned with a special agent before the repair. Cut a sufficiently large patch from the remainder of the foil you used, if you still have some in reserve. Then spread the adhesive from the repair kit onto the film and the patch. It should then act for five to ten minutes.

Stick double-sided special adhesive tape for rubber foils on the prepared patch. Under no circumstances should you use normal double-sided tape, it is not elastic enough. Then stick this patch absolutely crease-free on the EPDM foil on the pond. You should be able to press on easily with a wallpaper roller.

Prevent

How can I protect myself from water loss in the future?

So that your garden pond is always well filled in the future, you should avoid all things that cause the water level to drop too quickly. Check the planting regularly and cut back too lush bank planting in good time, preferably in autumn. This already reduces evaporation for the next winter. In spring you can also divide plants that have grown too large, such as cattails or reeds. Perhaps you will find grateful buyers for this in your relatives or in your circle of acquaintances.

If the capillary effect was the reason for the low water level, set a capillary block. Check the filter system regularly. If a hose is brittle or leaking, replace it immediately. The same applies to defective or incorrectly installed connections.

Capillary barrier

How do I set a capillary barrier?

It is best to create a capillary barrier when building the pond, because then the workload is relatively low. Cut the PVC or EPDM film very generously. Dig a trench about six inches wide around the pond basin. It should be about six to eight inches deep. Line the basin and trench with the foil and fill in coarse gravel. Instead of gravel, you can also use lean concrete or build this barrier from concrete slabs.

If you have failed to create a capillary barrier, you can also build this barrier afterwards. If the foil used is large enough, then proceed as described above. If your liner is not sufficient for the required digging, you can use a prefabricated pond edge system. The approximately 14 to 20 centimeters high plastic profiles are available in stores by the meter. There are also suitable plastic posts.

Drive the stakes into the ground about 50 to 60 centimeters apart around your garden pond. If the distance between the piles is too large, the profiles could be pushed outwards by the water pressure. Then attach the profile tape to the posts with screws. With the help of a spirit level, you can check the correct position of the profiles and adjust them if necessary.