Any pond makes an impressive addition to a backyard, but let’s face it – the most interesting part of owning a pond is watching and interacting with the fish.
But it’s not as simple as dumping a few fish in the pond and hoping for the best. The size of the pond, combined with the local climate has a major impact on whether the fish will thrive for years to come, or quickly go belly up.
If you live in a climate that doesn’t experience winter, then you almost have limitless options to stock your pond with. This article mainly focuses on fish that can survive in an area that experiences some form of winter – from only a touch of frost in the morning, to the bone chilling north, where the water freezes almost completely solid.
Recommended Pond Fish
Goldfish – Minimum Pond Size 250 Gallons (1136 Litres)
The goldfish is a staple of both pond and aquariums, and is a hardy and undemanding fish that is perfect for beginners. What you may not realize about goldfish, is that they can grow to enormous sizes if they aren’t confined to a goldfish bowl. It’s not unusual for a goldfish in a pond to exceed 12 inches (30 cm) in length and some have been recorded at sizes up to 18 inches (46 cm).
Because of their large size, any pond containing goldfish should provide ample space and strong filtration to ensure that they remain healthy. A good rule of thumb is to provide 50 gallons (227 litres) per goldfish, and to ensure that they have enough swimming space in a pond, the minimum size of a pond should be 250 gallons (1136 litres).
They will also survive in a properly winterized pond, and they will survive in a pond that completely freezes over, as long as the it is at least 4 feet in depth (1.21 metres) and the design encourages enough oxygenation – either through design or aeration.
Koi – Minimum Pond Size 1000 Gallons (4546 litres)
There are few fish that look more stunning than an adult koi in a pond, and no fish is more prized for its unique patterns are colors. Like goldfish, these fish can grow extraordinarily large in a pond, and it’s not unusual for them to reach 2 feet (0.60 metres) in length, with many growing up to 3 feet (0.91 metres) long.
Needless to say, a fish this large can only be housed in the largest of ponds, and the minimum size for a handful of koi should be 1000 gallons (4546 litres). The most commonly accepted way to determine how much space is required for koi, is to provide each koi with 300 gallons (1363 litres) of water, plus the minimum pond size of 1000 gallons.
Koi will also easily overwinter in all but the harshest winter environments. With that being said, any pond containing koi should be properly winterized, and should meet the minimum depth requirement of 4 feet (1.21 metres) to ensure that it doesn’t freeze completely during the winter.
The rosy red minnow is often overlooked as a pond fish, but makes an excellent addition to any small ponds and even many of the larger ponds. It not only boasts a bright and attractive coloration, but is easy to care for, and incredibly hardy.
One of the biggest benefits to stocking rosy red minnows, is that they are well adapted to cold conditions, and will over winter in a pond, as long as it is properly winterized.
They also breed easily in ponds, and they will constantly replenish their numbers. Even with predation in the pond, don’t be surprised if you constantly find your pond full of juvenile fish.
Mosquitofish – Minimum Pond Size 20 Gallons
The mosquitofish would never be called a flashy fish, but it does have its own unique charms. While it is mainly used to control mosquitos in smaller ponds, they make an interesting addition in their right. The males takes on a brilliant red hue when they are read to mate, and they are one of the only livebearer fish that can survive in cold water.
While they can tolerate cold conditions, unlike many of the other fish in this article, they will die if the pond freezes over. And that is pretty well the only thing that will kill them, and they can be found thriving in some of worst conditions – from blistering heat to stagnant low oxygen bodies of water.
Even with predation outside, they will usually quickly overpopulate a pond, so you should always keep an eye on their numbers. Luckily they are often in demand for mosquito control, so you should have no trouble giving them away if the need arises.
Sunfish – Sunfish are another overlooked pond fish, and in my personal opinion, make a better choice than goldfish or koi. Some species of sunfish colors rival the most colorful of cichlids and they are hardy and extremely well adapted to cold water conditions.
One aspect of sunfish that makes them perfect for ponds, is that they tend to congregate near the surface and in shallow water, so they are always in plain sight, and don’t tend to hide like some koi and goldfish do.
Some of the most popular species for ponds are bluegill, pumpkinseed (my personal favorite) and redear sunfish. You should do some research to determine which species of sunfish are native to your area, and those will often make the best choice for pond.
Many people that stock sunfish in large ponds, often include predators like largemouth bass to help keep their numbers in check. If sunfish are left to their own devices, they may quickly overrun a pond and become malnourished and stunted from lack of food.
It may be difficult to find a fish dealer to stock your pond with sunfish, but in most areas you can find large scale fish farms that will agree to sell small number of sunfish. If all else fails, you can always go fishing – assuming it is legal to transport game fish in your area.
Fish to Avoid
Catfish – While some people do report limited success with catfish in their ponds, most will ravage any plants, and will quickly turn the water cloudy from their constant sifting for food on the bottom.
If you do decide to stock catfish in your pond, the one species that some people have had success with are channel catfish. You should always stay away from bullhead catfish, or any other of large species of catfish (many of which may be invasive, and illegal to own anyways).
Carp – If there is one fish that you never want to put in a pond, it’s almost any species of carp. No fish will destroy your pond faster than carp, and they can destroy a carefully planted pond in a matter of days.
That’s not to say that carp don’t have their uses in controlling invasive plants in some ponds, or when being bred for aquaculture. But if you want an attractive and inviting pond, stay away from carp.