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Backyard Pond Tips: Adding Pond Fish to your Water Garden

180 Gallon Black Folding Preformed Pond/Streamlet Kit
180 Gallon Black Folding Preformed Pond/Streamlet Kit


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Why Have Fish?

Goldfish, koi, and ornamental fish add a flash of color to your water garden. They are entertaining to watch, are an important part of the pond eco-system because they help to devour mosquito larvae, and they can also eat some types of algae.

Introducing Fish Into Your Pond

Prior to introducing fish into your pond, there are several considerations you have to take into account:

Maintaining Fish in Your Pond- Oxygenate the Pond

Green Tip:

When planning your garden, include trees and shrubs. Placed correctly, they can reduce the heating and cooling costs for your home.

Fish breathe by extracting oxygen from the water through their gills. Therefore, the pond water must have adequate oxygen levels. Oxygen can be supplied by:

It is recommended that 60% to 70% of the pond be covered with floating plants. In hot weather, if there are not enough floating plants to keep the water shaded and cool, the water temperature will rise and oxygen will evaporate more quickly. Not only does more water need to be supplied to top up the pond, but an aeration pump, such as the UltraFlo fish pond pump, may be required.

Maintaining Fish in Your Pond- Monitor Ammonia Levels

Fish excrete ammonia, which is toxic to the fish. Ammonia is also food for algae and will encourage algae growth. To safeguard fish, and to preserve the natural eco-system of the pond, it's vital that nitrifying bateria be present in the pond in order to reduce ammonia.

The Nitrifying Cycle converts ammonia to nitrites.

In the nitrifying cycle, a bacteria called Nitrosomonas converts the ammonia to nitrites. Nitrites are still very lethal to fish, but another bacteria called Nitrobacter can convert the deadly nitrites to nitrates (which is basically fertilizer). Plants in the water, including algae, take nourishment from these nitrates and reduce the amount of nitrates in the water, rendering the water fish safe. Of course, the fish eat the plants and the cycle starts all over again.

A certain level of nitrifying bacteria occurs in pond water naturally, but it may be necessary to use a pond treatment to increase the level of nitrifying bacteria. Large fish ponds require biological filtration in order to provide adequate amounts of beneficial nitrifying bateria.

You should test your pond at regular intervals for Ammonia. These tests should be more frequent for new ponds because their eco-systems have not stabilized yet. An ammonia test kit can be purchased from commercial stores. The only acceptable reading from an ammonia test is "0." A temporary fix for a positive ammonia reading would be to change the pond water (remember to add "New Pond" to remove the chlorine and chloramines from the new tap water!).

A zero level of Ammonia can be accomplished by:

Maintaining Fish in Your Pond- Wintering Your Fish

Pond fish can either be taken indoors or over-wintered. For more details on how to take care of your fish over the winter, please go to our article on winterizing your pond.