If in doubt, under stock
Stock plants first, then fish.

Garden Pond Fish, Goldfish, Koi

What kind of Fish should one buy?

Buy common goldfish for a economical and easy start to pond ownership, Comets are a good first choice, as well as Shubunkins, Calico Fantails, Red Fantails, and Sarassa Comets.
Buy fish that are a minimum 3" long. The larger the better, as they have more resistance to stress.

Select gold fish because they are easy to see, hardy, and are compatible with aquatic plants. Goldfish multiply well. Goldfish are disease hearty and they are not bothered by extremes of temperature. The common goldfish varieties are also relatively inexpensive.

Choose 3" and larger fish because at this length they are adults capable of reproduction. Identifying sex of a goldfish is not important. You are bound to get a mix.

How many 3" Comets to stock?

Stock one fish for every 2 square feet of surface
area in your pond. So if you have a 25 square foot
surface area pond, get 12-13 fish.

Koi

Koi, or Nishikigoi (Cyprinus carpio), are descendents of the common carp. In nature they are brown, but through selective breeding by the Japanese, numerous colors and patterns were developed. In the 17th century Chinese rice farmers began keeping carp in their rice paddies. This practice found its way to Japan. The Japanese rice farmers begin to notice slight color variations in a few of the carp and bred these "mutants" into what eventually became what we now know as koi.

It wasn't until early in the 20th century that koi left Japan and were raised in Europe and eventually North America.

Koi normally attain lengths of approximately 2 to 3 feet and weight up to 35 lbs. Because of their large size, they should only be kept in larger ponds of at least 1000 gallons. Koi need excellent water quality to remain healthy. Sophisticated filtration systems should be used to maintain this water. Protect your investvent Koi are not cheap.

Koi that have been well cared for have a life expectancy of around 50-70 years and have been known to live to be over 200 years old.

How do I figure out how many square feet of surface area in my pond?

The best method is to take the length and maximum width measurements of your pond and make them the dimensions of a rectangle. It helps to draw this rectangle to scale, 1' = 1". Now divide the rectangle up into 1' squares. Next, sketch the shape of your pond inside the rectangle so that the extremes of the pond touch the sides of the rectangle. Now count the number of squares that are inside the pond. This is approximately how many square feet of surface area you have.This is a simple method that yields results you can use to determinr the approximate size of your pond. Another method is to use a rope or garden hose to lay on the outline of your pond. Then mark the length of hose, fasion it to a rectangle or square in your yard and calculate the square feet.

If you under stock, your fish grow larger than if you overstock, and increase in number
based on the size of the pond. This is a self regulating feature of understocking.

The concept follows that if you use this method to stock your pond, fish will grow and multiply to the limits the pond can naturally support. That is why it is wise to under stock in the beginning.

Buying Fish

When you first buy your fish, try to find a store where the owners have experience with ponds and pond fish. The reason why you want to buy from a knowledgeable fish supplier is that they can help you later if you have problems. There are also one stop pond equipment suppliers that can help you plan from beginning to end, including supplying fish and aquatic plants.

Acclamating fish to your pond

Goldfish and Koi are not affected by temperature variations. But, like all fish, they are very susceptible to illness if they are subject to rapid changes in temperature. Make sure the fish warm or cool slowly to the temperature of your new pond.

First, do not open the bags immediately upon receiving the fish. Simply put the bags in the pond or quarantine tank and let them float for at least 30 minutes so that the temperature of the water in the bag can slowly adjust to that of the pond water. If the bag is in direct sunlight, drape a towel over it to prevent the bag from overheating.
Make sure that the parameters of the pond water are acceptable for your new fish. Make sure that the water is dechlorinted and check the water’s pH, ammonia and nitrite levels.
After the bag has floated for the appropriate amount of time, open the bag and allow a small amount of pond water into the bag several times over a ten-minute period. This will allow the fish to slowly adapt to the chemistry of your pond water. Take care not to allow water from the bag to empty into the pond.
Gently remove the fish from the bag with a net. Place them into your pond, again being careful not to spill water from the bag into the pond.
Do not feed your new fish for at least 24 hours.
Koi may jump the first day when introduced to a new pond and should be monitored.

For the first few days watch for problems with your new pond fish. It will be obvious if you have a sick or injured fish. It will float sideways, swim in circles, orhave splotches on his gills . Losing a fish or two is no reason to panic. There are many other causes for stress in pond fish.

Nursing sick fish.

There are many treatments for sick fish. A good fish store operator will usually want to see the ailing fish before they recommend a treatment. Get a clean plastic bag, put in some pond water, and place the sick fish in the bag. Do not over handle the fish or it may lose its protective covering of secretions and become more vulnerable to disease. Take the fish quickly to a qualified fish store or veteranary service.

Try to treat a sick fish in quarantine if at all possible. Obviously, if what it has is contagious, you may need to treat the entire pond.

Fish feeding

Be careful not to over feed your fish.

Over feeding increases the waste produced by fish and raise amonia levels in the pond.

Determining what and how often to feed your fish depends primarily on water temperature. In warmer water (60-85 degrees) the metabolism of the fish is high and they can be fed 2-4 times per day. At this time you should be feeding a food with a high protein. If the water rises to 90 degrees or above you should stop feeding. In spring and fall when your water temperatures fall to 50-60 degrees, you should reduce feeding to once every 1-2 days and feed a low protein food.

When the temperatures in your garden pond drops to below 50 degrees stop feeding the fish. On warm days the fish may become active and "beg" for food. Do not feed them under this scenario. If the fish do need a little food, they will find enough growing in the pond. The algae that coats the pond liner is all they need. These cold temperatures slow the metabolism of your fish and food will not be properly digested. It can take 3-4 days for the fish to digest the food. It's not worth the fish's life to give it food.

Some experts advocate not feeding goldfish at all (not Koi), of course, this works only if you have properly stocked your pond with aquatic plants.

Koi

Goldfish and Koi are from the same carp family. Koi are bred and raised for numerous color patterns and, most of the time, sell at exorbitant prices.

Koi are notoriously rough on plants. Koi are generally nervous, fast moving fish. They eat a lot and and produce a lot of waste. Koi ponds generally have few plants in them, and need to be equipped with a bead filter to clean the water.

Koi provide a special situation that needs lots of care. Start your pond with goldfish only if you want to have an easier time establishing your Garden pond or want to save money. Later, when everything is going well, and your eco-balance is in good order, then you might want to add a small koi or two.

Algae

There are no better scavengers than goldfish. Most fish eat the algae that grow on things, the walls of the pond, the planters, and on other plants etc. But that is not the algae you want to get rid of. That algae can only be controlled by robbing it of its natural food source. See Maintenance.