If you have fish in your pond then no we would highly recommend you keep your pond pump on at night.
On the other hand if you do not have fish in your pond you can turn of your pond pump at night.
Why do you need to run a pond pump through the night
Your fishpond needs clean water for your fish to survive and be happy , if you don’t run your pond water through a filter system the water will soon start to get dirty and toxic, it’s your pump’s job to feed the dirty water to your filter system and it’s your filters job to clean the water before it goes back into your pond, so it needs to be running all the time.
Many people think turning their pump of at night will be ok, but what happens is you end up running your filter system for as little as 50% of the time.
If you turn your pump of at 9.00pm at night and turn it back on at 9.00am in the morning that means your pump and filter system is only cleaning your pond water for 12 hours a day which can lead to trouble further down the road.
What happens when you turn your pond pump off at night
So let’s say you only run your pump through the day and turn it off at night, what actually happens to your pond.
For a time you probably won’t notice much, the pond looks good and the fish are healthy.
But as time goes by the pond will start to get murky, the toxins will start to build up causing your fish to get sick and in many cases your fish could die.
The reason why this happens is that the filter system which is fed by the pump is only doing half a job, through the day one part of the filter cleans the water from dirt and debris, another part of the filter removes deadly toxins that build up from fish waste and a third part will kill algae that turns pond water green.
At night when the pump isn’t running the water isn’t being fed to your filter system so no cleaning is taking place, not only that but the good bacteria that removes the toxins from the pond needs a flow of water to keep them alive, if they die they can’t remove the toxins which is fatal for your fish.
So let’s say you only run your pump through the day, to start with the filter can cope, but as time goes by it starts to struggle, by day it just about manages to clean the water, but when the pump is turned off at night the waste, algae and dirt starts to build up, when the pump starts up in the morning the filter has all the build up from the night before to clean up before it can start cleaning for the day, the longer this goes on the more the filter struggles to clean the water and after a while the filter just can’t keep up with it.
Your pond is now dirty, the toxins are making your fish ill and to cap it all off the water has turned green.
At this point most people will turn to chemicals to try and sort out their problems, but all they are doing is masking the problem instead of curing the problem which is simple, keep your pond pump running day and night 365 days a year, your pond will look great and your fish will thank you for it.