Need a predator to control koi population

[fishbone]

My dad has a 5000+ pond. It is about a foot deep at one end going all the way up to above one's waist at the other. At this end the water never freezes all the way and this is where the koi spend the winter. He's got a waterpump with filter, which feeds a waterfall at the deep end.

The problem is overpopulation. Every spring the koi reproduce. We found a couple of people that offered to take some off our hands but we also thought we should introduce some sort of predatory fish that will grow no bigger than 4 inches [so he won't start harassing the bigger koi] that will hunt and eat some of the offspring.

The question is, what kind of fish should we look for? Could this fish spend the winter in the pond? It would be preferred but if not, it's not a problem since we can accomodate it indoors in our 75g aquarium. What should we feed said fish once he manages to feed off the smaller koi?

[Gump]

Dont know how good of an idea adding a predator to a small ecosystem like that would be. I think it would be better to have a predator in the 75 in the house and fish out koi you dont want and feed it that way or sell them.

Since your in nebraska you could add some native panfish to the pond that should eat the small koi and maybe koi eggs as well as what ever you feed the koi so they dont die off when all the small koi are gone. A problem i could see with this is one i dont think would do the job that great and if you add more than one you could run the risk of having them blow up your pond with fry too.
bowfin are an option but get larger and might not take pellet/flake food so you would have to feed them something else most of the year when there arnt any small koi.

[BV77]

Not necessairly an answer, but a question.....How bout a turtle?

[mayastarocker]

Wouldn't the turtle eat some of the bigger koi?

[BV77]

of course that depends on size of fish vs turtle

[Gump]

The turtle no mater the size would still nip the fins of the large koi.

[Niki2105]

What about selling them online? Would that be an option. Im sure there are lots of people that would take some off your hands.

[Scuba Kid]

Well my idea would be to get a channel catfish.
You can usually buy them in the summer at a pond store, usually albinos are readily available. They do get large though (around a few feet) but they would eat small koi and probably eggs, but IME don't go after large koi and goldfish. My uncle has two albino channel catfish in his large pond, one probably over 2 feet and the other around 1.5. He has never had problems with them attacking his grown koi and goldfish. I also plan on getting one for my pond this summer.

[fishbone]

And once the smaller ones are gone, what do you feed it?
Does it have to be brought in for the winter?

[flamingo]

Originally Posted by Scuba Kid

Well my idea would be to get a channel catfish.
You can usually buy them in the summer at a pond store, usually albinos are readily available. They do get large though (around a few feet) but they would eat small koi and probably eggs, but IME don't go after large koi and goldfish. My uncle has two albino channel catfish in his large pond, one probably over 2 feet and the other around 1.5. He has never had problems with them attacking his grown koi and goldfish. I also plan on getting one for my pond this summer.

I've caught channel cats around here that are about 4 feet long or more....

Personally, i'd go with a smaller species of pickerel if you just need something that will pick off the few inch koi. They're pretty peaceful- but most pickerel are piscivorous and will definitely eat smaller fish. Selling fish online, etc. is also good if you can pull it off- there are usually a lot of people that would be willing to take a few off your hands if you haven't already tried doing so.

I wouldn't put a predator in there myself, but those are my suggestions....

[Gourami Swami]

I like dylan's suggestion for outdoors, but it would be a good idea to to put a school of 3 hujetas in the 75g year round, and fish out any baby koi you dont want. I know channel catfish can get in excess of 4 ft.

[Scuba Kid]

For a pond over 5000 gallons, that's fine...

No, it would not have to be brought in for the winter. They will eat almost anything, so pond pellets or whatever you feed your koi would be fine.

[Gourami Swami]

But it may eat some koi he didnt want to be eaten, no?

[flamingo]

They may take a snap at medium sized koi... as for adult koi, they'll probably just nip fins. Around here, they live aside carp in the lakes- they don't hurt them but they do compete for food and just like bullheads, nip at fish.

Idk, personally i'd just go with something smaller that doesn't have the potential of controlling things. I get bullheads like that all the time. They go from cute little fish, to 5 inch devils that take over the tank. Just my opinion.

[import_nation]

buy swarms of RBPs and use them as feeder fish o.0

[Sue Gremlin]

Koi are sold for a lotta money, is there a LFS that will buy some? I'd call around.

Most people have a problem with great blue herons snacking on their koi and seek a way to deter the herons.