Checklist to Prepare your Pond for Fall and Winter

Published on August 17, 2009


Understanding how to transition the pond through the seasons is very important for you and your pondkeeper customers to understand. With the right techniques and products the change will be easy and seamless. Follow the guidelines below to better understand the process.

Educating your customers on the importance of preparing their ponds for the fall is one of the most important conversations you can have. As air temperatures begin to drop, so do water temperatures. During this temperature change, the needs of pond fish are altering as well. It is very important to protect the fish from their changing surroundings including falling debris and decaying leaves.

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Be sure to take some extra time with your new pondkeepers who are entering their first fall/winter season with their pond. It is probable that they aren’t even aware of what needs to be done and why. Additionally, you want them to come back to you next spring for their spring prep; therefore, it is your job to ensure a successful fall and winter. Remember, you are the expert and your advice is the most important they will receive!

Fall Feeding – Planning Ahead

In most parts of North America, water temperatures start to dip in early fall (September/October). Make sure your pondkeepers have a thermometer so they can monitor the water temperature as the fall weather progresses. Prepare your customers by explaining how to start changing fish diets to accommodate the changes these cold-blooded creatures will undergo. Wheat-germ-based food is ideal to transition fish in (and out) of winter because it is highly digestible at low temperatures. This is especially important because in the colder months, fishes’ metabolism and the pond’s ammonia-reducing biological activity are greatly diminished.

Prepping the Pond

Remind your customers that fall is the time to clean out their pond (before water temperatures fall below 50°F). This is recommended since the fish will still be active and less likely to sustain injuries during cleaning.


Scoop up fall leaves from the surface with a fine net. Your pondkeepers may want to pump some of the water out of the pond to expose the planting shelves around the pond periphery. This will make it easier to hand remove leaves that have adhered themselves to the pond edges and shelves. Using a hose nozzle, blast off the accumulated debris and sludge around the pond shelves and edges, and then remove remaining debris with a net or pond vacuum. When replacing the water after cleaning, remind customers to add a water conditioner to remove harmful contaminants like chlorine, chloramines and heavy metals.

Once the pond is clean, this is a good time to add a pond net if there are trees nearby to protect it from falling and blowing debris. Advise customers to suspend it at least 18˝ above the surface. Securely fasten the net around the edges to prevent leaves from finding their way underneath it. However, if your pond owner has frog inhabitants, it is helpful to leave a small opening or two to provide them access to and from the pond. Avoid letting the net sag into the water. Not only will it create a hazard for your fish, but leaves will collect in the submersed area and decay.

Don’t forget the plants…

Plant life can also be a source of debris. As marginal and deep-water aquatic plants begin to die back, prune dead stems and leaves to prevent decay in the water during the winter.

In late fall, recommend removing non-hardy aquatic plants like Water Hyacinths or tropical lilies from the water. Customers can store their plants in warm, frost-free conditions, like indoors, until next year.

For marginal plants in baskets around the perimeter of the pond, move them to deeper water to prevent them from freezing in pond ice. Hardy water lilies can be left in deep end of the pond over the winter. Bog plants can be insulated with straw or a commercial insulating material.

Winter Prep

Preparing a pond, and your customers, for the cooler, winter months is an important part of the relationship you’ve established. Most pondkeepers either don’t know what to do to prepare their pond for the off-season, or are unaware something needs to be done–until it is too late. Your customers are looking to you to know how to close up the pond, what equipment they will need and how to care for their fish during these months.

Close up the pond for the winter

The first step for your pondkeepers is to determine when they should shut down their pond equipment: the pump, filter and UV clarifier. If your winter temperatures are moderate, your pondkeepers may continue to run their pumps to keep the pond surface from freezing. Further north, where temperatures are more extreme, you’ll want to recommended shutting the pond down for two reasons. First, the pump will mix colder surface water with the slightly warmer, more stable temperatures in the pond bottom where fish take comfort and hibernate. Second, pond owners risk the chance of diverting water out of the pond and emptying it when the flowing water begins to form ice, especially on features like waterfalls or streams.


Recommend that your pondkeepers store their equipment indoors safe from the elements. It’s also a good idea to clean and inspect the equipment and replace any broken components. When shutting down the pumps, filters or any other equipment remind your pondkeepers if they are storing the equipment outside or in an unheated space make sure that there is no water left in the device that may ice up and cause the body/housing to break. If kept inside it helps to place the pump, if it is submersible, in a bucket of water to keep the moving parts and seals wet.

Winter Pond Equipment

It is important to recommend and stock a de-icer product. Take the time now to educate your customers on the importance of investing in a de-icer; waiting until their pond freezes over may be too late.

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 Gases, which are produced by decomposing organic material, are toxic to fish when they are trapped beneath ice covering the pond’s surface. De-icer’s are designed to keep an area of the pond ice-free during the winter, allowing harmful gases to escape through the opening. In small ponds, a de-icer is especially helpful in preventing ponds from freezing solid. For fish safety, it is extremely important to never break ice on the pond because the shock waves can be detrimental, and sometimes fatal, to fish.

There are energy conserving de-icers designed specifically for ponds that are inexpensive to run. As an alternative, you can advise them to melt a hole daily by setting a heated pan of warm water on the surface. Either method of creating an ice-free opening will let pond inhabitants breathe, maintaining their health and longevity.

Remember, winter can be stressful on a fish’s immune system. De-icer’s alleviate stress during the winter, making it easier for them to withstand diseases that are more prevalent in the spring.

Caring and Feeding Fish Throughout the Winter

In most parts of the United States it’s best to leave fish in the pond during the winter, providing the depth of the pond is adequate (18˝ or deeper) and there is little or no water circulation. The denser, warmer water will sink to the bottom of the pond, where it will be insulated by the cooler surface water or ice, and fish will gather in this deep, warm area. It’s important to advise your customers, however, that some types of fish, such as fancy goldfish with ornate tails, bubble eyes and lionheads, are sensitive to cold weather and should be brought indoors.

As winter approaches, pondkeepers should monitor pond water temperatures daily. When the water temperature falls below 39°F (editors note: many koi keepers stop feeding koi when water temperatures fall below 50°F), pondkeepers should stop feeding the fish altogether. First-time pondkeepers may worry about not feeding their fish, but you can assure them that their fish will naturally rely on stored energy reserves to sustain them throughout the winter months.

Remember to go through this checklist with your pond customers. Taking these few steps now will ensure their fish will survive the winter and they are sure to enjoy a successful pond season next year.

Fall/Winter Pond Checklist

To ensure you cover all of the necessary fall pond prep steps with each customer, keep this checklist handy:

• Reduce the number of leaves falling into the pond with netting or remove them with a pond net

• Clean out the pond as outlined above

• Cut back dead or dying aquatic plant foliage during the fall

• Purchase a wheat-germ-based pond food developed especially for a spring and fall Diet

• 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 (in northern climates in risk of ponds freezing over). It will melt a small opening in the surface, allowing noxious gasses to escape.

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8 thoughts on “Checklist to Prepare your Pond for Fall and Winter”

  1. Hello, I live in Ontario, temperature at present usually around 52-70 F in daytime and around 40F in night time, these couple days is particular cold, 39F in day time and 25F at night time, however, the next few days will be back to normal usual temperature of 52-55F in day tie and 39-43 F night time.

    Can you tell me if it is too late now to bring in some of my Koi at this temperature as there are too many Koi outside in my 4000 gallon ponds, have four 1 ft. ones, fourteen 6-7 inches ones and around thirty 2 ins. babies this seasons.

    I already catch back (Thirty 1 1/2 in babies and Thirty 1/2 in. babies earlier September, and was about to catch some more early October, but temperature suddenly drops fast. I do intended to leave the four over 1 ft. one outside, and try to catch back half of the medium sizes one and all the babies that is still outside right now, but the temperature suddenly turns very cold.

    If they are already hibinate right now, will they goes back to normal condition if I catch them back now and put in the aquarium and fish tank that I have in the basement?

    Please kindly advise, or is it better now to leave them alone now.

    Also, I brought a 150 watt. aerator which consists of 4 air disc and is in the water right now, is it too much disturbance to them. I will be putting in a 350 watt. de-icer soon as soon as I cut back all the lilies and irises next Tuesday when it will be 59F in day time, scope out any dead leaves and refill part fresh water, and then cover up the pond from fallen leaves with net.

    Should I put the de-icer right on top of the aerator or I should just put one disc of the aerator only with the de-icer so not to disturb the water too much.

    I would appreciate it very much if you can help and give me some advise ! Thanking you in advance !

    Angel Height

    1. Avatar photo

      Response from Jamie Beyer:

      It is okay to bring the fish inside any time of the year. However, the colder the water the longer the acclimation period to bring them up to the temperature of your indoor aquariums or tubs. I usually take 12 to 24 hours to bring the temperatures of 40 degree water that the fish are in to 70 degrees, which is my indoor temp.

      I rarely use a deicer. You can use one if you want to satisfy yourself — no harm other that its 350 watts of power being used that I view as being wasted. I always use an aerator but with only a good bubble from the airstone – not a boil of rising air bubbles. You do not want your fish fighting a current all winter. The aerator that you described is much too big for winter use. It would be great for summer use. The aerators I use are 5 watts.

      Good luck Jamie

    2. I was wondering how to blow the lines out in order to prevent them from freezing and the lines bursting.
      I am a new home owner, and the house come with a pond. I’ve never owned a pond before I called some pond companies but they are fully booked until the end of November. I live in Ontario, and I was wondering if I can do it on my own. Thanks.

      1. Avatar photo

        From Jamie Beyer:
        Every situation on “blowing out water lines” is somewhat different. However, there are some similarities. You use compressed air to accomplish the task, of course. Hooking up the compressed air is the key to being successful. I have PVC couplings that I have adapted to fit my portable compressed air tank fittings. These fittings then fit onto the piping that is being blown out. The fittings that you need will depend on what size piping you have.

        I have three large portable compressed air tanks that I use. You can rent these if you do not have one or two.

        An easier solution that I have attempted to do in all my installations is to provide a drain line (valves) in piping that could hold water when shut down. I also try to provide a slope to piping so it naturally will drain when shut down. Of course, if you have any kind of check valving (one way valves), these will need to be bypassed or taken off.

        There seems to be always some situations where lines still need to be blown out. Irrigation lines are ones that always need to be blown out is one example.

        Have fun water gardening. Jamie

  2. I’m a new pond owner and i have 3 koi. Two are older then the baby i just got. It’s now first nob and i live in Hot Springs, Arkansas and the temp is 46 and just started to get cold last couple weeks. The water temp is 53 but will drop tonight to 36 and stay like that for probably awhile. Should i get a heater for them? The water is only about 2ft deep in one end of it and like 10 ” in the other end. What should I do?

    1. Avatar photo

      From Mark Gibson:
      Your fish will be fine as long as the water pump is running. I recommend an aerator for your pond though if you are worried about it. You should have no problem. Good luck!

  3. Hi I am from Ontario southern . It gets cold here and I have a pond 13 x 7 feet . I have about 28 small and some bout 8 inches koi and goldfish . It is about 2.5 feet deep un the center. I had it netted until almost all leaves have fallen . I have removed the filter and uv pump , I left a small air pump with a small air stone and purchased a deicer that floats. Will this be enough maybe? It is the first year to leave them out as before I had a little pond with 8 and I put them in an aquarium inside . I also bought a small water pump and dropped it in without a hose but now I am reading its best not to circulate the bottom waters , Should I take it out and leave just the deicer and the small air stone do you think ?

    1. Avatar photo

      Hello Nancy,
      You are in a location that gets extremely cold for a long time. That means you must have first class wintertime life support in place. A small air pump and air stone along with a floating heater is inadequate. In my opinion, at 28 small fish in a shallow pond, you need better winter life support. Start with a larger air pump (something 45 lpm) and bigger air stones (use 2). This will gas off any CO2 in the water and constantly keep your water at a high quality. A floating heater as a back up is a very good idea. In your situation a 1,500 watt heater is mandatory. Your water will stay 33F all winter long because you will have a covering of ice. Mixing the water at the top with water at the bottom cannot change water temperature. Your floating heater does not actually heat up your pond water either. The way we keep our fish alive under ice all winter is to provide good quality water for them. Hope this helps!

      Richard Heimberger
      Healthy Pond
      Visit Me On Facebook

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