The best time to winterize a koi pond is early fall, before the first hard freeze and while the water is still cooling. Scheduling pond maintenance now gives your fish and equipment a calm start to the cold months, and our water feature team in Otsego, MI sees the best results when owners plan ahead.
Here's what you need to know about getting your pond ready for winter.
Let Water Temperature Set the Schedule
The calendar is only a rough guide, because your pond's water temperature is what your fish respond to. A simple pond thermometer tells you more than the date on the wall.
Fish slow down as the water cools, so fall prep should start before winter temperatures arrive. Pond care makers recommend doing your before freezing weather sets in.
Clear Out Leaves and Plant Debris
Leaves that sink to the bottom break down over the winter and foul the water. That is why pond care pairs so well with your fall leaf cleanup schedule.
Trim back aquatic plants so dying leaves do not fall into the water. If you are planning new plantings for spring, these plants for your pond are a good place to start.
Decide What Happens to the Pump and Filter
Pumps, filters, and pond lights that could be damaged by freezing weather are usually pulled and stored for the season. A clean filter stored dry is ready to go when spring arrives.
Some owners keep a waterfall running, since moving water helps delay freezing. That choice depends on your pump, your plumbing, and how cold your yard gets.
Keep a Hole Open in the Ice
Your pond should never freeze over completely, because fish need gas exchange at the surface. A floating de-icer keeps a small opening clear without heating the whole pond.
In a cold Michigan winter, a de-icer is often the simplest way to keep that opening. Check it after big storms, and top off water lost to evaporation.
Let Your Fish Rest Near the Bottom
Koi and goldfish can stay outside all winter in a properly built pond. They settle near the bottom, where the water stays a few degrees warmer than the surface.
That happens because water is densest at about 39 degrees, so below the ice. A small opening at the surface lets those fish rest undisturbed until spring.
When to Call a Pro
A fall visit from a pond crew takes care of the heavy work in one trip. It is also a good time to spot liner wear, loose rocks, or filter problems before they get worse.
R&A Landscaping is a certified Aquascape landscaper, and our water features team handles everything from fall cleanings to new installs. If you are weighing spring service too, this guide on whether to hire a pond cleaning service can help you plan the full year.
Frequently Asked Questions
Should I keep feeding my koi in the fall?
Slowly cut back feeding as the water cools, then stop once your fish quit coming to the surface. Their metabolism slows in cold water, so they rest near the bottom and do not need food until spring.
API Fishcare suggests switching to a lower-protein, cool-water food once the water drops below 65 degrees.
Is it safe to leave a waterfall running through a Michigan winter?
It can be, but it takes more attention than shutting down. Moving water helps delay freezing, and the pump has to keep running through every cold snap.
In very cold areas, a floating de-icer is often the safer choice. Either way, keep checking the water level and add water as it evaporates.
How do fish survive under a frozen pond?
Fish survive because a pond freezes from the top down, leaving liquid water below the ice. Water is densest at about 39 degrees, so that slightly warmer water settles at the bottom where your fish rest.
A pond needs enough depth for that layer to hold, plus an opening at the surface so gases can escape.
What happens during a fall pond cleaning from R&A Landscaping?
Our crew drains the pond to about six inches and moves your fish to a holding tank. We powerwash out sludge while leaving the beneficial bacteria on the rocks.
We also remove debris, clean light lenses, trim plants, and clean the filter pad and bio balls. Then we refill with dechlorinator and return your fish to a clean home.
When should pond netting go on?
Pond netting should go on before the leaves start to fall. R&A Landscaping offers netting with autumn cleanings, using a thin net that keeps leaves out while preserving the look of your water feature.
Once the trees are bare, you can take the net off and store it for next year. That keeps most of the season's debris out of the water.
Get Your Pond Ready for Winter with R&A Landscaping
A little planning this fall means healthier fish and an easier spring opening. Let our pond and water feature contractors in Otsego, MI handle the cleanup, netting, and equipment prep for you.
Call R&A Landscaping today at (269) 694-1331 or request a consultation online.