skip to main content
Summer Special - Quote 'FREEP' for FREE Delivery on 35 Spend or over

8 Common Pond Mistakes

Pond Maintenance can be difficult, as there are a lot of areas to consider. We have listed below 8 common pond mistakes which, if treated, can improve the quality of the pond.

23 August 2021

Having a pond with crystal clear water can be difficult; but not impossible to achieve. Clear water can only be achieved with routine maintenance and suitable equipment; this helps to prevent algae blooms (green water), cloudy water, sludge problems and a lack of aeration. When the water becomes murky or green, the pond is exhibiting symptoms of a chemical imbalance. Below are some common pond maintenance mistakes that you should avoid.

You may also find our ‘5 Tips Which Can Make A Big Difference To Your Pond’ blog post useful.

FILTRATION: Incorrect equipment / Low UV 

One of the most important things you can do for your pond is to purchase a suitable pump and filter. A filter should always include UV, mechanical and biological filtration (some smaller filters suited for ponds under 4500 litres may not include the biological filtration). In short, a UV bulb keeps your pond free from algae blooms and it can kill other harmful bacteria which may cause various infections; mechanical filtration removes debris like sludge; lastly, biological filtration allows healthy bacteria to break down Ammonia, Nitrites and Nitrates. All three steps are crucial to keep a pond clean and clear; more information on filters and their maintenance can be found in our blog post ‘Filters & Their Maintenance’.

There are two main types of filters: box filters and pressurised filters. We always recommend box filters for any ponds that contain Koi or Goldfish, whereas a pressurised filter should only be used in ponds with Goldfish or wildlife. Your pump and filter system should be filtering your water every hour for Koi and Goldfish, or every two hours for a wildlife pond. This allows your pump and filter set to keep the pond clean, clear, and free of problems.

Insufficient Adjustment Time

When you have just set up your pond, the chemical balance of the water will take time to adjust. This is because the pond will go through the ‘Nitrogen Cycle’. It is a natural process where debris decomposes and forms Ammonia, which is turned into Nitrites and then turned into Nitrates. If you regularly test the water, you will see various spikes of these chemicals. Even using chemicals in these early weeks can cause a slight imbalance, so it is best to leave the pond water for at least 6 weeks to allow healthy bacteria to grow.

If you intend on adding fish to the pond, it is best to do so after a few weeks of setting the pond up. Or to add fish in smaller batches over several weeks. This is to reduce the impact of fish waste on the chemical balances of the pond.

You can find more information on the chemicals of pond in the below links:

Water Quality

New Pond Syndrome

FISH: Overcrowding / Overfeeding

Depletion of oxygen and a build-up of ammonia are major factors for algae blooms (aka ‘Green Water’). When there are too many fish, they use a lot of the oxygen, which can be dangerous to both fish, plants, and wildlife. Further to this, having too many fish can create problems with too much sludge; sludge can decompose and affect the chemicals in the pond and increase the amount of maintenance your pond requires.

Further to the above, having an overstocked pond means that you will have to feed the fish more often and in greater quantities. Regardless of how many fish you have in the pond, overfeeding can cause excess waste, which decomposes and forms sludge, which leads to high ammonia levels in the water.

The combination of low oxygen oxygen and high ammonia will lead to more severe algae blooms. To avoid this, feed your fish only what they can eat in 3-5 minutes once a day. They will remain healthy and keep your pond water healthy and thriving.

You can find more information on Green Water and algae blooms on our blog post ‘Green Water and Slimy Algae’.

How to Oxygenate a PondAerating your Pond

Many pond keepers face problems with aeration; mainly because a lot of pond keepers don’t aerate the water enough, particularly during the summer months. A lot of problems caused by a lack of aeration are normally linked to other problems, so it isn’t an easy problem to diagnose.

Essentially, if you see any of the below problems re-occurring on a regular basis, it is likely that your pond needs extra aeration.

-Fish gasping at the surface of the pond or at any entry points for water (Waterfalls, fountains, streams).

-Foul odours - decaying organic matter (Fish waste, plants, sludge) can indicate that there is a lack of oxygen, water movement or filtration.

-Rapid algae development - This can be a sign of poor aeration and filtration.

It is very easy to aerate a pond too; most people will include a fountain, waterfall, plants, or a dedicated mechanical air pump. While mechanical air pumps are the most efficient ways of aerating a pond, pond keepers across the country prefer alternative methods for aesthetic reasons; having a waterfall can introduce a focal point and the sound of running water can help to provide a calm, relaxing area. Plants are also really good at being a focal point, while creating an area for fish or wildlife to gather around.

You can find more information on aeration, and its benefits, in the blog posts in our ‘Air Pumps’ section.

SLUDGE: Build up of decaying debris

Decaying debris at the bottom of your pond can help to fuel algae, which in turn changes the colour of your pond to green. It is quite common for this to happen between February and October. Manually removing any debris, dead leaves or decaying plants will help to reduce the amount of sludge in the pond, which in turn reduces the chemical impact upon the pond. See below for the various ways to keep a pond clean of sludge:

-Having a suitable pump and filter – These will remove most of the debris which falls to the bottom of the pond.

-Cover Nets – These are extremely useful at preventing leaves and plant debris from entering the pond; which has a huge impact on preventing algae blooms and sludge from forming.

-Pond Maintenance Nets and Poles – If you don’t like the idea of a cover net for the aesthetic reasons, you can always purchase a pole and net like the Swap Net Set; this will allow you to skim the surface for debris.

-Pond Vacuums – These are electric vacuums, very similar to a household vacuum, which removes dirt and debris from the bottom of the pond. Some vacuums even include a discharge basket, which can filter the water for sludge. An example of this would be the PondXpert PondMaster and Discharge Basket Deal.

-Skimmers – Skimmers are surface devices that pull debris from the surface of the pond and locate it all in one, easy to access location. While you will have to empty the skimmer regularly, it won’t take very long at all.

If you are experiencing any problems with sludge and debris, you may find our blog post on ‘Pond Sludge: How to Prevent and Treat It’ useful.

Partial water changes

Partial water changes are recommended at the beginning of the pond season (February-March) as they can help to remove harmful chemicals and replenish the pond with clean water. A partial water change of 5% should also be done once a month in the summer period (June to September), as this can keep the water balanced. It is not advisable to do a water change greater than this, unless there is a specific reason for this (such as evaporation, fish diseases or excess silt). You should also dechlorinate any water you put in; a popular product for this is the PondXpert Tap Tonic.

Runoff and poor drainage

The combination of excessive rain and poor drainage is a danger to your pond. When rainwater enters your pond, it can disturb the balance as the rainwater may contain pollutants from the air and chemicals and fertilizers from the soil. A great preventative measure is to build a “lip” around the edge of the pond.

Not enough shade

Natural shading is important in the design and construction of a pond. Too much direct sunlight can cause temperature change and algae blooms so plants like water lilies and using floating planters will help to prevent the algae developing from the heat.  About 50% of the pond surface should be covered ideally.

If you need any further assistance, please contact us.

Newsletter Signup

Receive internet-exclusive offers, discounts and previews by email.

Tips and Advice from the Blog

Latest Tweet

© Copyright Pondkeeper 2005 - 2021. Pondkeeper is registered in England, Registration no. 5601027. Our VAT number is GB 875 4886 60.

See the site map | privacy policy | terms and conditions.

Website created by Edward Robertson web design with the Responsive Grid System