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How to maintain your garden pond?

Guide written by:
Jeremy, construction site supervisor, Cardiff

Jeremy, construction site supervisor, Cardiff

118 guides
Water turbidity, oxygenation and trimming plants are all maintenance tasks that are required to preserve a garden pond's ecosystem. Spring, summer, autumn, winter: upkeeping a garden pond is different depending on the environment, the atmospheric conditions, the water temperature  and the amount of sunshine. 

Important features

  • Maintenance of the filtration system
  • Outdoor pollution
  • Oxygenation
  • Water turbidity
  • Plant maintenance

Why should you maintain your garden pond?

garden pond's ecosystem is a subtle balance between a multitude of living organisms. Water-borne plants, insects, fish or bacteria contribute just as much to the purification of the water as they do the degradation of water quality. To keep your pond's water of good quality, clear and oxygenated, and thus promote and develop organism that have moved in, you must ensure that regular maintenance be observed.

The most important parameters to maintain are:

  • The oxygen level (02);
  • The total suspended solids (TSS);
  • The pH and hardness of the water (to a lesser extent because it rarely changes) 

Both the water temperature and the amount of light coming in also play a crucial role. The warmer the water, the higher the reproduction rate of the organisms it contains. This starts a chain reaction that results in all these organisms consuming a significant amount of oxygen from the water in an attempt to ensure their survival and growth. In the same way, the presence of light promotes the photosynthesis of plants and they too will consume oxygen to grow and develop.

The consequence of the uncontrolled growth of all these living organisms is the transformation of any useful elementt into waste. Whatever is left over will increase the total suspended solids  in the water, rendering it  cloudy and tainted, algae could even settle (the concept of hypertrophication). It is therefore imperative to treat the water to maintain this precise balance. The environment around the pond can also be a contributing factor in the decrease in water quality, whether that be via dead leaves off of overhead trees, dust, or wildlife (birds, amphibians, rodents etc.). A clean garden pond, with good quality water, is a simple question of routine maintenance.

Primary garden pond maintenance tasks

Filtration system

Essential for oxygenating and filtering the water, your pond's filtration system must be selected carefully and maintained regularly. Its filtration capacity must match the volume of water to be treated, while also taking into account any inhabiting fauna and flora.

Filters must be cleaned and rinsed at least once a month, even more regularly in summer. If the pond is equipped with water jets or a fountain, the different nozzles should also be cleaned, preferably at the same time as the filters.


Gravity filtration system

If the pond is equipped with a gravity filtration system, the settling tanks will be drained at the beginning and end of the season, most commonly in April and October. Whichever filtration system you end up selecting, it's important to regularly verify that it is perfect working order (no suspicious noises, leaks or vibrations). You can also purchase a convenient water tester kit to check the oxygen levels and pH.

Just in case it may be of need, the conventional oxygen level for pond water ranges anywhere from 8 to 12 mg/l (milligrams per liter). The pH should be around 7 (neutral). For the TSS, testing is more complex but the water turbidity is a good indicator that there are too many suspended solids in the pond.

Maintenance of a garden pond per season

Like we discussed above, the water quality also depends on the incoming light and the water temperature. Regulating these two elements will require different tasks depending on the season.

Garden pond maintenance in spring

The filtration system is normally shut down at this time of the year. As soon as the water temperature reaches 10 ° C, restart it. You can also check that everything is functioning properly.

Trim the plants around the pond and its edges to promote new growth. Replant new ones if necessary.

Using a pond netclean the surface of the water and dispose of dead leaves and other debris.

If there are fish present in your pond, check their general well-being.

Restore the pond's water level to where it needs to be if necessary.


Garden pond maintenance in summer

This is the time of year that requires the most work. It implies the regular cleaning of the filtration system, the nozzles (if you have water jets or fountain), and the verification that all the devices are working correctly.

Check the oxygen level once or twice a month (once a week if you have fish) and kill two birds with one stone by checking the pH at the same time.

Regularly clear the surface of the pond of any duckweed, algae and floating debris.

Trim the plants. If yours is a fish pond, check that the fish are still in good health. Restore the pond's water level to where it needs to be if necessary.

Garden pond maintenance in autumn

It's time to prepare for winter.

Clean the filtration system one last time and make it an especially thorough cleaning, to last all winter. As soon as the water temperature drops below 10° C, turn the system off.

Feed your fish more regularly so that they can stock up for winter.

If possible, use a landing net to the surface of the pond to prevent dead leaves from falling into the water.

Refill to the desired water level one last time.

Garden pond maintenance in winter

It's a sleepy period for your pond. The fish are at a slower pace and the plants aren't growing anymore.

Trim the plants one last time if needed and protect them from frost .

Regularly clear off any dead leaves from on the surface of the water (with a pond net or the landing net installed in autumn).

Stop feeding your fish.

Stop the filtration system (if you have not already done so) as soon as the water temperature drops below 10 ° C.

If the possibility presents itself, an anti-freeze protection can easily be improvised by tying a plastic sheet or tarp to the surface.

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Guide written by:

Jeremy, construction site supervisor, Cardiff 118 guides écrits

Jeremy, construction site supervisor, Cardiff

Electrician by trade, I first worked in industrial estates where I installed, wired and fixed a large number of electrical installations. After this, I managed a team of electricians for this type of work. 10 years or so ago, I turned to building and construction. From the modest family home, to gyms and theatres; I have been able to coordinate, audit and organise all sorts of construction sites.

for 4 years now, I am restaoring and bulding an extrension to a bungalow in the heart of the welsh countyside. My experience in manual work and my knowledge means I am proud to be of service. Terraces, interior design, roofing, plumbing, electricty, anything goes! We have, my wife, daughter and I, built almost everything we have from scratch! So to answer all of your questions, and to orientate and advise you on coosing your tools? Easy!

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