The Best Fish to Stock a Pond With and Why

What is the best fish to stock a pond with?

Mosquito fish are the most important fish for any pond because they eat mosquitoes and their larvae. Contrary to what many think, these fish highly reduce mosquito populations on your property. While these fish are prolific and reproduce quickly, they also serve as food for larger pond fish.

When it comes to adding fish to your pond, there are many options to choose from. The question isn’t only about your personal preference. It’s also about what fish are most suitable for your particular situation. They must contribute to the ecosystem rather than putting a strain on it.

Creating a properly functioning ecosystem

In order to create any kind of successful pond, it must have a properly functioning ecosystem. Without a properly functioning ecosystem, all sorts of problems develop over time. Some will be noticeable right away while other problems occur in the long-term.

The Best Fish to Stock a Pond With and Why

It’s important to address these situations before they happen in the first place. That’s the right way to do it. I have a page dedicated on how to build a functioning pond ecosystem which is found HERE. I highly suggest you read it. You must have an understanding of what it takes for a properly functioning ecosystem to develop.

Problems that may occur with a week ecosystem include some of the following:

These are only some of the problems that occur with an ecosystem that’s not up to speed. Ideally, your ponds ecosystem acts as a filter, pump, oxygenator, and absorbs of organic waste including both plants and animals. An ecosystem is not a hard thing to build but there are certain rules you must follow. You must build your ecosystem from the bottom up. Check out this diagram to the right which gives you a general idea of the pecking order an ecosystem must have in order to succeed.

Build a Pond Ecosystem
Start at the bottom and work your way up (over time).

Fish for your pond

Now on to the fun stuff. Assuming that you have a properly working ecosystem, we’re going to go over some fish that should work well with your pond. We’ve already covered how important mosquito fish are. Now, this goes for any pond no matter what you intend to keep in it. While highly prolific, if populations of mosquito fish become too great you can always remove them with a net and possibly sell them to your local pet store. Alternatively, you can add a pond predator that keep their populations in check. Proceed with caution when adding predators. Predators are at the top of the pyramid for a reason. 

Koi and goldfish

The number one fish people choose to keep in their pond is without question Koi and goldfish. There are a few things to keep in mind when keeping these fish. First of all, don’t overstock your pond with Koi or goldfish. These fish become rather large and produce copious amounts of waste, including ammonia. If you have your pond overstocked with Koi or goldfish, ammonia levels become a problem.

The solution is simple, simply keep your koi and goldfish populations minimal. This means keeping them at a number your pond’s ecosystem can handle. Otherwise, you’ll be dealing with water quality problems among other issues. Manually keep these populations in check by adding only a few at a time to see if your pond can handle them. If the water remains crystal clear, you may add another fish or two, just don’t go crazy with it. Another important piece of advice, don’t overfeed them

Adding game fish to your pond

Game fish is another popular fish that people add to their ponds. There are a couple of golden rules that go along with keeping game fish. First of all, game fish need a lot of space. Basically, we’re talking about largemouth bass, bluegill, perch, and even to a certain extent some species of large minnows. Only a larger pond will suffice when it comes to keeping game fish, preferably even the size of a lake. They need a lot of space to swim around.

Water depth

The water depth must be at least four feet deep in northern states. In warmer states such as Florida where the water does not freeze over completely, three to three and a half feet in water depth is fine.

When it comes to pond construction the general rule of thumb is, the bigger and deeper, the better. However, (and this is important) if you have children or those who live close by, it’s best to keep your pond shallow for obvious safety reasons. Sometimes you have to make sacrifices for the safety of children. Their lives are far more important than our ponds.

It’s also a good idea to have your pond fenced-in. Where I live, all ponds must be fenced by law. I agree with this law and have no problem with it. A child’s safety comes first. Always keep a close eye on children around any body of water.

What about adding trout to a pond?

Fish such as trout can also be kept in a pond. They need a large body of water with a pump so the water constantly cycles. Trout also need cooler water temperatures. I’m not sure how well they would do in a warm state such as Florida.

Back when I was a freshman in high school, I had a friend who had a pond with a large waterfall in his backyard. Keep in mind this was upstate New York, about 30 miles north of New York City. He caught a trout and placed it in his pond. The water in the pond was well circulated by both a pump and a large waterfall. Another advantage included living in a climate trout are accustomed to. The tout ended up surviving long-term.

When you have a pond set up the right way it can properly maintain trout, although I wouldn’t recommend it unless you live in a cooler climate. The water must have plenty of circulation and oxygen. I suggest having a pump, and a waterfall if possible. Trout also need a large area of space to keep them happy. 

Tropical and subtropical fish

It may seem like a good idea to stock your pond with tropical and subtropical fish that you can buy at a local pet store. First of all, you have to keep in mind that tropical fish need warm water conditions to survive and thrive. With subtropical fish, you have a little more wiggle room.

In northern states, I would say the chances of tropical fish or even subtropical fish surviving in your climate are slim to none. On the other hand, subtropical states like Florida have much more suitable climates for (at the very least) subtropical fish. In northern Florida, tropical fish most likely won’t survive in an outdoor pond. However, there are some species of subtropical fish that can survive a north Floridian winter. You have to be very careful about this though. There are laws against releasing such fish in waterways, especially the public ones and those owned by the state.

Other issues with invasive fish

If you live in an area where heavy downpours of rain and flooding occur, your fish may escape two other waterways. If this is a possibility, avoid it altogether. Even when you have a pond nowhere near any public or state-owned waterways, fish are sometimes transported from one pond to another by birds. While this seems like a longshot, it’s totally possible.

This is why I generally recommend against keeping subtropical fish in your pond. It’s best to go with fish native to your area. There are other advantages to keeping fish that are native to the area. Such fish have natural camouflage to protect themselves from common pond predators. These include nuisance animals and birds. In the end, there is still plenty of fish to choose from when adding them to your pond.

Conclusion

Make sure to stock your pond with mosquito fish first. These fish keep mosquitoes from an infestation in and around the pond. Your neighbors will thank you. Koi and goldfish are fine as long as you don’t overcrowd or over-feed them. Trout need well-circulated, highly oxygenated cooler water. Other game fish such as bass and bluegill need larger bodies of water, at least three to four feet deep depending on your climate. 

The Best Fish to Stock a Pond With and Why