Like everything in nature, the rhythms of your garden pond change with the seasons. If you live in a climate that's warm throughout the year, there may be little additional maintenance needed, but for those in variable climates, seasonal pond maintenance is essential to keep your plants and fish healthy.
Spring Pond Maintenance
Nature is getting ready to kick into gear again, and so should you and your pond. If you live in a climate where you had to shut down your pond for the winter, it's time to prime the pond for warmer weather. Once water temperatures reach about 45 degrees, inspect, clean and install your filtration system and pump. Check hoses for leaks and motors for proper operation. Use some biological additives to give your pond's beneficial bacteria a jump start.
Once the ice thaws, test your water and use any chemicals or additives needed to create the proper balance. The water is more likely to be out of balance during the spring as your pond comes back to life. If you have high levels of ammonia, drain about 25% of the pond and replace with fresh water, using a dechlorinator if needed.
As the water temperature warms, reintroduce your plants so that they are established to help combat algae growth. You can also start to fertilize your plants with fish-safe fertilization pellets. Expect some algae blooms during the first few weeks if temperatures are warm. Once the fish and plants become more active, the algae should clear up.
When the water temperature reaches about 50 degrees Fahrenheit, you can start to feed your fish again. Fish won't eat at temperatures below 45 degrees, and decaying food will spoil the water, so hold off on feeding until the temperature is right.
Spring is the best time to clean your pond, especially if you've moved your plants and fish indoors for the winter. Drain the pond, clean the sediment from the liner, then refill it and test the water before adding any plants or fish. You'll need a dechlorinator if your community adds chlorine to your tap water, and the disturbed sediment may contribute high levels of ammonia or nitrogen.
If you dredge your pond instead of draining it, siphon off some of the water, let the sediment settle, then test it before returning fish and plants. If your fish spend the winter in the pond, wait until they're active and feeding daily before removing them, and keep them in some water from the pond until they're ready to be put back.
Summer Pond Maintenance
Summertime is algae time. In order to combat algae, add a waterfall or other water-moving feature to your pond. Oxygen is an algae enemy, so anything that aerates the water helps to control algae growth and provides adequate oxygen levels for your fish. Keeping the water moving will also keep the pond cooler and prevent mosquitoes from breeding.
When it comes to feeding fish, the best advice is don't do it. Letting the fish feed on algae and plants is much healthier for your pond because it cuts down on fish waste and toxic chemcials released by uneaten, decomposing food. If you must feed the fish, only give them enough to eat in a few minutes and skim off the leftovers. If the pond was closed during the winter, you may need to feed a little at the start of the season, but once algae and plants start to grow, feeding should be discontinued.
You are likely to have more evaporation now than at other times of the year. Monitor the water level in your pond and keep it filled. Don't forget to check for chlorine and salt levels whenever you add water. You can expect the water level to drop a bit each day if it's hot, but any sudden drops should be investigated, as they could be a sign of a tear in your liner or a subsidance in the ground beneath your pond.
If your water temperature reaches 85 degrees Fahrenheit or more, stop feeding your fish. If the water stays hot for several days, consider draining and replacting 25% of the water to lower the water temperature.
Fall Pond Maintenance
In most parts of the United States, fall means leaves dropping. You need to keep these from settling to the bottom of the pond, as decomposing leaves devour oxygen and cause nitrogen levels to spike. If you're just dealing with a few leaves, daily skimming may be enough. Another option is to use netting above the pond to catch any falling debris. Be sure to check pumps and filters every few days to make sure they're not clogged with leaves.
In areas where you have cold weather during the winter, do a large water change, up to 50%, to remove contaminants from the water when the air temperature and water temperature are about the same. Be sure to do this before the water temperature drops below 60 degrees Fahrenheit, when fish will start to slow down. Treat your water with winter weather conditioners.
Take out any tropical plants that will not weather well, bring them into your house and place them in water for the winter season. Trim back hardy plants such as water lilies and place them in a deeper part of your pond.
When your water temperature drops to 45 degrees, remove your filter and pump. Clean and store them for the winter according to manufacturer's instructions.
As the fall season starts to cool your pond, cut back fish feedings to once a day. When the temperature hits 40 to 50 degrees, stop feeding your fish until spring. If your pond is three feet deep at one end, fish will be able to overwinter safely outside. If it's shallower than that, you should bring the fish indoors for the winter.
If you live in a warm climate, stop fertilizing your plants when the water temperature dips below 70 degrees. Continue with your normal maintenance during the fall season.
Winter Pond Maintenance
In cold climates, you must make sure that your pond does not completely freeze over. There must be a hole in the ice so that oxygen can get into the water. If your pond freezes over, your fish will die. Use a winter pump to keep a hole open. If you live in an area where the temperature stays below 10 degrees consistently, you should install a thermostatically controlled heater near to the pump to help keep an opening in the ice.
In warmer climates, stop feeding your fish if the water temperature drops below 50 degrees Fahrenheit. Take out any tropical plants that can't tolerate colder temperatures and store them in water indoors.
Mosquito fish are a great natural solution to the problem of landscape pond insects, but you'll need to take some steps to keep your fish healthy.
Pond leaks are not fun. Noticing a water level drop, you are sure you face repairing your pond liner. Before you panic, make absolutely sure it is a leaking liner and not another problem.