How long can fish survive without a pond pump?

How long fish survive without a pump really depends on the weather; though in general, if your pond does not have a pump or if the pump breaks, it should be resolved as quickly as possible as this will benefit the fish.

In general, a pond pump is useful for several reasons. It can pump water to a filter (meaning sludge, debris, and algae are removed) and it can oxygenate the pond water. For both reasons, a pump is a vital piece of equipment that allows your pond to harbour fish in a safe environment.

If your pump is faulty or if your pond does not have a pump, it is likely that sludge will build up and the oxygen will deplete; over time, this will allow toxic chemicals to build up and you may experience fish loss.

Further to this, oxygen is a significant part of your filtration process. The oxygen encourages healthy bacteria to thrive in your pond, which in turn breaks down your sludge and turns it into harmless chemicals. Without a pump, not only is the water not being filtered, but the healthy bacteria in your pond can deplete.

Which season is it? (Useful Blogs: Why Temperature plays a big role in Pond Development)

If your pump is faulty during the winter, it is likely that your fish will survive for a while because they are hibernating. They will produce less waste; use less oxygen and they will have a lower metabolism. They will also require less attention and the colder temperatures will increase the amount of dissolved oxygen into the pond, making it a lot safer for your fish throughout the winter period.

Alternatively, if your pump breaks down in summer, this could be a problem. Because the temperature is higher and the fish are more active, they will be more oxygen-hungry. The worst-case scenario is that you may see some fish die within 24 hours; though if you have an air pump (which is advised for all fishponds!) your fish are more likely to survive.

How to add Oxygen? (Useful Blogs: How to Oxygenate a Pond)

If your pond has a high stock of Goldfish and Koi, it is best not to rely heavily on one piece of machinery to provide all of your ponds various needs.

For instance, you should not be relying on a single pump to keep your pond aerated. As if the pump becomes faulty, this vital source of aeration is gone and you may not spot this problem straight away. You can add oxygen to your pond through a variety of methods; though mechanical air pumps, pond plants, waterfalls, and fountains are generally the most efficient methods to include.

If you see any of the following signs, your pond will need extra oxygen:
• 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.

You may also find the below blogs useful:
• Pump Maintenance & Troubleshooting
• Pond Pump Maintenance
• Why is my Pump under-performing?
• Bacteria: The Importance of Healthy Bacteria
• Air Pumps Blogs

If you have any queries, please email us on info@pondkeeper.co.uk.