Like any aquarium, a pond has a filter, and basically the rules for filters don’t vary.
The filter has to be cleaned to function properly. Disassemble the parts of your filter that can be taken apart, and wash in a solution of aquarium salt and water. This disinfects these parts in order to get rid of any parasites or bad bacteria. Do not clean your filter medium entirely. Leave some of the good bacteria in the medium because it’s important to start fighting the bad bacteria that has built up over the winter. Pond filters are usually in the form of sand or sponge. If you have sand, put it in a bucket and add clean water until it overflows the bucket. This will easily wash away the loose sludge. With sponge, rinse it with a hose to remove the surface sludge.
Getting Rid of Debris in Your Pond
Use a net to scoop out all the debris that has built up over the winter. Be sure to drag the net along the bottom because leaves, twigs and bugs sink to the bottom. This is important to get as much out as you can, so there won’t be a strain on your filtering system. Then continue to clean up plants by taking off dead leaves, and stems or other parts that need removing. Don’t throw any dead plants. Give them a couple of months to start over or to see if anything can be saved from them. Fertilize the plants and place them in the spots where you want them growing in the summer.
Feeding Your Pond Fish
In the spring, your koi and goldfish start to stir. Feedings should not start until the air temperature maintains at least 60F during the day. If you feed fish while the water is still too cold, they will not eat even though they are moving slowly. They need time to get totally out of hibernation. Uneaten food will cause bad bacteria and you will end up washing your filters all over again.
Consequences of Neglecting Your Pond
If you don’t maintain your pond, expect bad things to happen such as scum that can kill fish and smother plants. Unkempt plants can deprive your fish of oxygen and sunlight. If the water becomes stagnant, it will attract mosquitoes and other insects. Have you ever smelled stagnant water?