A good time to do this is in the fall. Pond life is at an ebb and things are slowing down after a busy summer growth season. Just try to start your autumn maintenance routine before it gets too cold because messing with cold water can be unpleasant for you and the inhabitants of your pond. Not to mention when trying this in freezing conditions you’ve just upped the degree of difficulty unnecessarily.
Remember too that what you can or have to do depends on the type of pond and it’s size. Backyard ponds built on preformed pond liners are more suitable for an all out clean out annually. These ponds are typically smaller than those using flexible pond liners. So you’ll likely have fewer fish to disrupt ideally. Yes, you do also want to consider the fish plus any pumps, filters etc you’ve got in operation.
Why bother? Well, making sure that the water is clear is one way to tell that the pond is healthy. You don’t need to worry how to go about this because I have some really simple steps that you can do yourself in cleaning your own pond.
First, you need to remove all the koi or goldfish. Get a bucket, and fill it with some water from the pond itself. Then net the fish and transfer them the bucket and then to a fish tank, the size of which depends on the size of the fish, where you will house your koi fishes temporarily. Obviously this won’t work if you have huge fish. After all the koi and other pond fish are transferred to a fish tank, still reserve some water from the pond for later use.
Second, drain the water on your pond. With smaller ponds you can use a wet dry vac to suck the water out. You do not have to remove all the water but if you want to clean everything well, it’s better drain it all out.
Koi Pond Tip: If it gets cold where you live, as a favor to your fish you would do well to invest in some kind of pond heater. Don’t forget koi are more carp than goldfish. While they can adjust to cold and ice by slowing down their metabolic rates, they hail from more temperate climates . So they would prefer backyard ponds with more comfortable water temps, at least in the deep end of the pool where they will tough out the winter. This is made easier on them if you provide some heat.
Third, you can now clean the pond. You can simply do this by using a clean hot water and maybe a power washer to blast the algae away. This is also the time tol remove all elements in the pond like rock and unwanted plants. Make sure to clean your filter as well at this point.
Fourth, rinse your pond. Fill it up with clean water and drain it. Do this at least two times to wash out everything.
Lastly, fill up the pond and put all the koi back after clearing the chlorine out of the water.