Goldfish Koi Ponds

Goldfish Koi Ponds make fish keeping easy

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Goldfish Koi ponds are rewarding. Both types of fish are much more at home in a pond that has plenty of surface area with plenty of surface activity, such as water fountains and falls. Goldfish average one inch of growth per year with Koi leading the way at three inches per year. There’s no aquarium large enough to house even one mature Koi, reaching as much as three feet in length. Many people purchase Koi not realizing their growth potential. The same holds true with goldfish, even though they typically reach a third of the size of Koi at maturity, it would take a giant aquarium to house an old school of goldfish. Most common goldfish that survive their goldfish keepers end up being released in nearby lakes or ponds

goldfish koi ponds
Goldfish and Koi Ponds

The standard stocking level for both fish is 2.5 gallons minimum per inch of body length. Stay at or below this standard to keep a healthy natural balance of the ecosystem. Double the amount of water, and cut the inch in half to cut maintenance in half. The bigger your pond; the lower your stocking levels; the easier it is to maintain

The larger the pond, the less maintenance required to keep the water healthy, but just like aquariums and indoor tanks, the stocking levels also dictates how much maintenance will be necessary

Goldfish Koi ponds

When your goldfish spawn, reduce the amount of food you’re feeding. The fish will feed on the eggs and any small fry lucky enough to hatch, controlling their own stocking level. Keep in mind, your fish will never stop growing, and as they age, the size of your pond may need to be increased, or fish re-homed in order to maintain a healthy stocking levels. Exceed the stocking level for too long, and the ecosystem may become unbalanced, leading to an unhealthy environment


goldfish Koi ponds
Goldfish Koi Ponds
goldfish koi ponds
Goldfish Koi Ponds

Common, comets or shubunkins are much better suited to outside ponds than the delicate fancy variety, but even the fancies can fare well in a pond with the proper care

Goldfish Breeding

Goldfish are cold blooded; meaning they have no core body temperature, so it’s important that the depth of your pond is below your regions freeze line. This provides an area that the fish can migrate to in freezing or even warmer weather conditions

goldfish koi ponds
Goldfish Koi Ponds

In some parts of the world it may be advisable to bring your goldfish in during the colder winter months; unless you have a heater for your pond

Never chop a hole in a pond that has been frozen over; the vibrations may damage the fish internally by rupturing the swim bladder organ or the central nervous system

Keeping goldfish save from predators

Most predators interested in goldfish and Koi are nocturnal. Our freshwater fish are diurnal, meaning they rest when it’s dark. Being bottom dwellers by nature, they should be safe from nocturnal predators. This is one good reason to have an adequate depth in your outdoor pond. A deeper pond not only provides a safe haven from predators, but can also offer cooler water in the summer and warmer water in the winter

If predators are a problem in your pond, it may not be deep enough, or the water may be low in oxygen, and the fish are spending time at the surface where they are vulnerable. Carbon dioxide, a gas created from waste, hangs heavily on the bottom, keeping oxygen from entering, forcing fish to swim higher in the body of water than what they normally would be. Only a real pond pump provides the proper kind of action to eliminate Co2 from pond water

Goldfish and Koi both are at risk of becoming a tasty treat for neighborhood cats, dogs, raccoons and herons. The water table should fall 8″ to 12″ below the edge of the pond in order to keep them safely out of reach. It’s also helpful for the ledge to hang out over the water, offering another hiding spot. This will also prevent goldfish from leaping out of the water during spawning sessions. Motion activated sprinkler systems work well in deterring these predators

If you live in the city, it may be regulation to fence in your pond to avoid accidental drowning of neighborhood children. Your own children or grandchildren may be at risk, so watch the little ones carefully

If you are considering building a pond, the use of fresh concrete and mortar may leach harmful chemicals into the water. These materials must be cured for 6 months to a year depending on your climate. If the KH (carbonate) levels in your freshwater source are on the high side of the comfort zone, avoid using concrete, as the lime concrete is made from increases these levels

Algae in Goldfish or Koi Ponds

Goldfish ponds have a distinct advantage over aquariums when it comes to algae, looking more natural in the outdoor setting, enhancing the beauty of the pond and the health of your goldfish or Koi. Algae gives a new pond an aged look. In a fully cycled pond, algae helps to create an almost maintenance free environment, because the plant feeds on nitrates just as other vegetation, but no other plant can match it’s voracious appetite for the toxin

Algae also offers a healthy food source for goldfish. If your pond has a thick lining of algae, you may not ever have to feed your fish. Algae is mother natures way of icing the cake to the nitrogen cycle. With the help of algae, you could create a pond that requires very little effort to maintain  Algae the Living Plant

If the pumps in your pond are established with beneficial bacteria, nitrates, the end result of the nitrogen cycle, are being produced. Where you find nitrates, algae forms to feed on the toxin. This is extremely beneficial in an outdoor pond

If your stocking level is low, nitrate production should also be low, and you may not have to exchange much pond water, however, it’s always necessary to add water that has evaporated. We call this topping off the pond. This act also keeps the mineral content higher. The biggest mistake pond keepers make is overstocking

In a cycled pond, test for nitrates regularly to make certain your fish aren’t at risk for nitrate poisoning. Safe levels are 10 to 20 ppm. Test regularly for nitrates

Locate your new pond in an area of your yard that is free of falling leaves or debris. In the fall, leaves can quickly cover the water’s surface reducing oxygen levels. Leaves and even pine needles that are not soon removed leach tannin into the water which is toxic to goldfish

 Outdoor Goldfish and Koi Ponds

Your goldfish or Koi are only as healthy as the water they live. Test the carbonate and general hardness to make sure your goldfish are living in quality water.  Read all about the value of water in the 10 steps to goldfish keeping. Follow each step faithfully, and this will help you create a healthy ecosystem and healthy fish

10 Steps to Goldfish Koi Keeping

Every pond, no matter what size should include a pond pump, two or even three in the set up. A simple pond pump that sits on the floor of the pond is all you need. The intakes should be wrapped with aquarium safe sponges, and rinsed in old pond water regularly. The more complicated the filtration system, the more difficult it will be to maintain

Every pond should also include a natural gravel substrate. Pea gravel will help buffer the minerals in the water, give waste a place to settle, and give your goldfish the pleasure of pecking through it; a favorite past time. In an aquarium, a gravel vacuum is used weekly to eliminate waste, but if your pond is large, and your stocking level low, monthly vacuuming is all that should be necessary. Use a gravel vacuum with a hose attachment to increase suction

Make sure your ponds receives indirect sunlight throughout most of the day and most importantly, make certain your pond has plenty of water movement

Photograph; courtesy of Gwen. A wonderful example of an above ground pond. Stock tanks, whether indoors or outdoors make great goldfish containers; they’re large; they’re tough and they’re also affordable, however, they’re not insulated, and the water may become too warm in the summer or too cold in the winter. These types of tanks are better suited for indoors in most regions unless you’re prepared for some additional work

Wintering Goldfish and Koi

Goldfish and Koi are cold blooded. They become dormant in colder temperatures, so they don’t mind the cold weather. The temperature of their bodies will be the same as the temperature of the water. The colder the water, the slower the fish. As their metabolism slows, so does their digestive system. Dormancy begins at 64f, so as the water temperature drops, offer food that is easily digested, feeding less and less at mealtime

Toasted wheat germ, peas, blanched spinach or green leaf lettuce make healthy cold water snacks. Designed to improve digestion, gel food is a safe bet if your fish are cold and hungry

If you have algae in your pond, this is a wonderful food source rich in roughage, and if there’s enough of the vegetation to see the fish through winter, there’s no reason to continue feeding. If the fish are interested, offering a snack is okay as long as it’s the right kind

Goldfish and Koi ponds

When you measure the temperature of your pond, place the thermostat on the bottom to get a reading

As the temperature lowers, and your fish eat less food, they’ll produce less waste, but this isn’t a problem for the colonies of beneficial bacteria living in your pumps and filters because they too become dormant in colder temperatures, so they need less waste to feed on

As water temperatures rise and fall in a healthy pond, a spike in the cycle should never have to be part of the event as long as you feed according to the water temperature. There are very few regions that are consistently cold throughout winter. It’s typical to have a run of warm weather or maybe even two or three. When the weather warms, look the fish over, test water parameters, perform a water change. Treat the fish to a tonic to enhance their health

The larger the body of water, the more consistent the water temperature

Leave the pond pumps running throughout the winter. Moving water is much slower to freeze over. If your pond’s depth reaches to the freeze line, the bottom will stay just above freezing, and the fish will be just fine after the thaw. Slow feeding and feed foods higher in roughage at 64f; stop feeding at 54f

Goldfish and Koi cannot withstand freezing temperatures, so make sure the bottom of your pond is at the freeze line in your region

In case of a power outage in the winter, there’s little reason to worry if the surface does freeze solid. It’s a myth that a hole must be cut in the ice in order for gases to be released. If your pond water is in good condition, and you have fed according to the weather; feeding less and less as the temperatures lower, the water should remain heavily oxygenated, and remain so for several days, if not weeks. Because goldfish and Koi become dormant in cold water, they eat less food, so less gas is created from the waste the fish produce. It’s this very attribute that keeps them from utilizing much of the oxygen in the water

The colder the water, the less oxygen goldfish and Koi need

Pond pumps sit on the bottom, and if your pond’s bottom is at the freeze line, there’s little to no risk of the mechanics freezing up, but it may be wise to wrap the cords with insulation to reduce the risks of breaks or cracks. Warm and cold temperatures take a toll on electrical cords

A freeze line is a point of depth in the earth that doesn’t freeze in the coldest average temperature for your region

Whether you keep goldfish or Koi in a pond or an aquarium, follow each and every 10 step so that your fish will grow and live

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Author: Brenda Rand