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Good Steward Post

Seasonal Pond Maintenance - Koi Pond Maintenance for Beginners (part 3)

For brand new koi pond owners the ins and outs of maintaining their new backyard ecosystem can be overwhelming. Good Steward Ecoscapes is here to help! If you haven't yet, read the other two articles I have written for new pond owners on basic pond maintenance (part 1) and routine pond maintenance (part 2). After reading those, use this article as a guide for seasonal koi pond maintenance to enjoy your outdoor living space year round!


Your ecosystem pond will ebb and flow with the seasons as they change. For those of us in northern climates, this is more extreme than those of us in moderate climates. As winter changes into Spring your pond is going to experience tremendous growth with string algae. This is happening because organic debris such as leaf litter and built up fish waste is decaying and releasing nutrients. The aquatic plants are still dormant so the only thing available to take up those nutrients is the algae. This is an opportune time to do a cleanout on your pond. The water needs to be drained, this fish need to be moved to a holding tank, the filters need to be cleaned, the rocks and gravel need to be rinsed of sludge, and all that debris needs to be removed for your pond to have crystal clear water again. Most pond owners opt to have a deluxe cleanout done which includes a power washing as well to clean off the string algae. After this cleanout, beneficial bacterias will need to be added to boost the pond's biofilter.


Throughout Spring and Summer the pond's water will warm. Your fish may spawn when the temperatures hit a certain point. Sometimes the spawns take and you will end up with new fish babies. My personal advice is to not feed the babies and let them forage for food in the pond, to help keep it clean! During this spawning event, you'll want to make sure you have fine filter material where your pump sits. This helps filter out the added organic material in the water.


Towards the middle of summer, some homeowners choose to clean out their biofilter to enjoy clear water. The sludge from fish waste and decaying food will build up in the filter, excess sludge can cause algae blooms and hazy water. Normally, if the pond is filtered properly and the fish population (bioload) isn't excessive this isn't needed. If you choose to do this, make sure you use water from the pond to clean the filters. Tap water has chlorine which can kill the beneficial bacteria in your filters, causing your filter to crash.


In my own pond I have noticed the string algae growth seems to be controlled by the time July begins. The trees are done releasing their pollen, the fish spawn is over, and I don't overfeed my fish so they frequently forage in the algae looking for bugs. Maintenance in summer is pretty simple. The growing plants are taking out excess nurtrients. The only real task that should be done regularly is removing dead waterlily flowers (I don't) and removing algae when it becomes a nuisance (I do this a few times during the year, that's it).



Fall is an important time for your pond maintenance routine. As trees go dormant, you'll need to prevent their leaves from falling in your pond and rotting over the winter and Spring. Most homeowners choose to put a net over their pond, others will go out with a hand net to scoop leaves out daily. Also very important, homeowners need to feed their koi or goldfish a cold blend food that has wheat germ. This food is easier for them to digest in the colder water and allows the fish to still get nutrients to prepare for their winter hibernation.


During Fall and Winter, pond homeowners can still use water treatments. There are cold water beneficial bacterias that thrive in cold water temperatures. Though dormant, the fish are still excreting ammonia; even when the water is cold, organic material is still breaking down. Another product I like to dose in the Fall and warmer periods of winter is sludge cleaning bacteria. These bacteria strains consume organic material so they help break down leaves and any excess fish waste, making the pond’s ecosystem much healthier for the fish.


Preparing for winter should be done during the end of Fall or beginning of winter. Around Chicago this is usually during November and before Christmas. Homeowners choosing to shutdown their waterfall filters should do so before the heavy freeze hits. Care should be taken as the plumbing needs to be completely empty so the water inside it doesn't expand and break the pipe. Many homeowners use a de-icer aerator combo in the pond to keep a hole in the ice so the fish don't suffocate. Some pond owners choose to not use a de-icer and only use an aerator. This comes with its risks as you may need to pour a pot of boiling water where your aerator is at least twice per day during a deep freeze - a heavy snowfall may make this difficult!


Ponds are a great water feature to have in one’s landscape. They can be enjoyed 24/7 365 days per year! Contact us today for a design consultation or for help with maintenance with your pond.


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