Gary, How To, Ponds

Autumn Pond Maintenance

For the life in your pond, autumn is a period of winding down after a busy summer. By the end of September, animal activity will have started to slow down and your plants will have completed their flowering and seeding. All this activity leaves a lot of detritus behind and now is the time to get started on the cleanup and get ready for the rest of the year.

Early – Late September: Protecting Your Pond

Leaves are a big problem for your pond as they start to fall from the trees and into the water. Too big a build up on the surface can cause oxygenation problems, and an overabundance of decomposing organic matter can throw off the ecological balance of the water (in extreme cases acidifying the water)  making it dangerous for the life in your pond. Prevention is better than cure in cases like this and your first line of defence should always be a net  or cover guard . In the case of a net, you will find that some leaves always get through, a few leaves won’t be a problem but be sure to keep on top of it by skimming your pond with a net or a surface skimmer.     

Late September – mid-October: Cleaning Your Pond

During spring and summer, your pond care regime should be focused on curbing the growth of microbes and algae in your pond, in Autumn,  the focus moves to the cleaning of silt and debris that build up in the water as leaves, seeds and insects fall into the water.

You should be cleaning your pond regularly as a matter of course, but a thorough clean around mid-October ( with a complete clean every 5 years)  is essential for an easy start to spring. Not cleaning out your pond will result in a springtime mess of silt and debris that result in a bog rather than a pond, you are also risking a blanket weed and algae problem once the days start getting longer.

An effective and thorough clean should follow these steps:

  • Start by preparing a holding tank for your fish in a shady area. Make sure you use some of the pond water in your tank (unless it is overly cloudy)
  • Drain the pond slowly: a pump is usually the easiest way of doing this, but use whatever method is best and easiest for you.
  • As the water level goes down, remove fish from the pond as they become visible with a dip net and get them quickly into the holding tank.
  • Do the same with any pond plants you come across  – use this opportunity to re-pot plants if you need to. marginal (water’s edge) plants will survive out of the pond as long as they are kept moist and shaded.
  • Skim and leaves and detritus from the pond with a net. Make sure to place decaying plant material on the side of the pond, so any smaller creatures can return to the water before you throw them away.    
  • Scoop up excess silt from the pond and dispose of some of it ( you can use this silt as a good fertilizer for your border plants) keep the rest in a safe place. You don’t have to be overly paranoid about getting everything because you will be returning some of the collected silt anyway to re-establish microorganisms.   
  • Clean the  liner with a scrubbing brush and water, bailing the dirty water out with a bucket (do not use soap)  
  • Return the saved silt and water to the pond. Refill the pond ( preferably with rainwater), positioning plants as you go
  • Carefully return fish and other creatures to the pond.

Prune plants of dead and excess leaves before returning to the water.

Mid-Late October: The Close Down – Preparing for winter

The later seasons of the year are the most shocking for pondlife, and you should use the tail end of autumn to make its life easier during winter. Giving your pond a headstart is pretty easy and you only need to take small actions to have a big effect.

The first changes you make should make are to plant life – start by moving your marginal plants to deeper waters to prevent them from freezing. Non-hardy plants like Water Hyacinths should ideally be removed from the water and kept in warm frost-free conditions until things start warming up.  

The diet of your fish should also change around this time of year, wheat-germ-based foods are ideal for the winter months as they are easier for your fish to digest in colder conditions. Moving to this type food makes your fish produce waste with a reduced ammonia content, meaning it won’t build up as quickly in the water whilst the ammonia eating microbes are dormant.

Your final task in preparing for winter is the closing down of your pond – this means closing down and shutting off all electrical pumps and UV clarifiers. This is an important step as pumps are likely to circulate cold water throughout the pond which can negatively affect the life inside it.  Closing down your pond is a simple process, the basic steps are to:

  • Disconnect the pump, filter and UV clarifier before water freezes
  • Store UV clarifier indoors for protection
  • Store filters indoors (if manufacturer’s directions suggest)
  • Purchase or have the pond de-icer ready for installation

Once done, you are all ready for winter and the unique challenges it presents. But until then there is plenty to be done in preparation. A pond can sometimes seem like a lot of work but come summer when the plants are in bloom and your fish are happily swimming in clear water you will be glad that you put the work in early.

Gary ClarkeGary works in the Primrose product loading team, writing product descriptions and other copy. With seven years as a professional chef under his belt, he can usually be found experimenting in the kitchen or sat reading a book.

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One Comment

  1. Joan Lacchin

    What very interesting & helpful reading, Thankyou! I am fairly new & had NishiKoi for over 6 yr’s, & also a pump/filter, & heater which unfortunately the Beast from the East cracked the latter, As it was all shut down for several months after my fish mysteriously died all together,. I kept the pump working for the waterfall for therapeutic reasons, I have had 6 Koi bought for me ( after all the cleaning youv’e suggested.My husband recently passed away & I would dearly love to keep the pump/filter with waterfall running as the sound of the running water is very therapeutic for me, Can you advise please. Regards Mrs Joan Lacchin

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