How to Winterize your Pond for your Fish

Did you know your goldfish and koi can stay outside in your pond throughout the winter? With the proper maintenance and preparation, you can keep your pond fish happy and healthy all year long.

It is important to perform maintenance in early fall before winter temperatures hit. This will include a water exchange (if applicable), adding bacteria like, API® POND-ZYME SLUDGE DESTROYER or API POND ECOFIX SLUDGE DESTROYER, removal of any filters, pumps or any lights that may get damaged in freezing weather. By adding in bacteria, this will help boost the biological filter to consume any waste or debris during the winter.

To be able to keep the flow of dissolved oxygen, you should not allow the water to completely freeze over. This may require a de-icer, an aerator, or a continuous movement of water (i.e., waterfall). The moving water will help delay or prevent the water from freezing. However, if you live in a location that gets extremely cold during the winter, then a de-icer is the best option. A de-icer is a heater (maintains water above 32°F) that floats in the pond and will keep it from freezing over while still allowing the gas exchange at the surface. 

During the winter months fish do not require the same nutrition. As the water temperatures start to cool down, we recommend to gradually switch over the pond fish food from API POND FISH FOOD to API COOL WATER FOOD. API COOL WATER FOOD contains less protein to be easily digested as their metabolic processes slow down. This should start when water temperatures are below 65°F. As the fish start to slow down and do not visit the surface as much, feeding can taper off. Eventually, when the fish stop coming to the surface all together, you may stop feeding them. No need to worry about your pond fish, this is a natural process for them. They become dormant in colder water, slowing down their metabolism and do not require food to feed their metabolism. It is common to see them slowly moving around the bottom. If the fish are no longer coming to the surface – there is no longer a need to feed them.

Other key tips to consider going into the colder months is to clean around the pond of debris and trim plants to keep them from falling into the water through the colder months. Covering the pond with a net will help keep leaves and other organic material from getting into the pond as well. Throughout the winter months, continue to check the water level and add water back to your pond as it evaporates. Make sure to dose the water with API POND STRESS COAT or API POND AQUA ESSENTIAL when you add tap water to dechlorinate the water making it safe for your pond fish.

Taking these steps will ensure your fish and pond can over-winter properly. They will thank you when warmer weather comes around!

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