Keeping koi in a well

[Dave39]

Hello.

I just bought a new house which has a natural well. It's a large brick well about 7' in diameter with the water level consistently at about 23' deep. I'm guessing it's somewhere around 6500 gallons of water. The previous owner had placed a few koi into the well several years ago, and those same 3 koi are still there, swimming happily up and down that well. I've no idea what kind of koi they are. I'm guessing these are just some common fish.

This well is fed by a natural spring and high water table, has no mechanical filtration at all (or really any filter of any sort). It's basically just a big hole in the ground. I can watch the koi swim down about 6' before they disappear. The water has a lot of suspended algae but really isn't all too bad looking. Water clarity isn't fantastic but it's not horrible either and supposedly, these fish have been here like this for years. The well once supplied water to the house many many years ago, but no longer does.

So I have a few questions.. knowing little about koi. First off, how many koi can I keep in the well before requiring a filter? And secondly, how should I control mosquitoes in this situation? Mosquito pellets? Mosquito fish? Gold fish? I know goldfish are related to koi but they seem awful messy. I'd like to just put a dozen goldfish into the well but I don't want to risk mucking up the water. I'd like to avoid a filter... I've looked at some that are rated for this much water and they start get pretty expensive.

Thanks!

 

[adavisus]

I would have thought on a permanent body of water there would be some natural predators about that would suppress if not eliminate mosquito. If there are dragonflies, water beetles, water spiders, pondskaters, whirligig beetles around, skeeters are there only long enough for lunch time...

While mosquito may look for and find ponds, a healthy permanent pond is in effect going to reduce the local skeeter population. Considerably


Regards, andy
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[Dave39]

I would have thought on a permanent body of water there would be some natural predators about that would suppress if not eliminate mosquito.

It's not a pond really. It's a large brick water well fed by a natural spring. The only predators are the koi, which from I've read are too large to eat mosquito larva. It's possible dragonflies may visit but I've not seen any. Of course, I don't see any mosquito larva either... I'm just trying to be proactive about it since I do have 3 small children. The well is securely covered with metal cyclone fencing and bolted down. No birds, racoons (or small children) can get in. And I don't see any other insects either.

 

[koiguy1969]

a small pump to keep the waters surface moving will get rid of the misquitoes..they like still or even stagnant water for egg laying. if this well is spring fed, and theres a constant input of fresh water it is possible that no filtration would be necessary...but mechanical removal of solids from the bottom woud beyond a doubt aid in maintaining water quality. you could hang planters from the well walls to give a little natural feel.

 

[Dave39]

a small pump to keep the waters surface moving will get rid of the misquitoes..they like still or even stagnant water for egg laying. if this well is spring fed, and theres a constant input of fresh water it is possible that no filtration would be necessary...but mechanical removal of solids from the bottom woud beyond a doubt aid in maintaining water quality.

There is definitely a constant input of fresh water. Although I've not drained it and timed how fast it fills, the water level never drops. I'm probably going to dredge the bottom just to see what I pull up and clean it up a bit.

How many more koi do you think I could put in there? Thanks!

 

[fishin4cars]

Adding a air stone or water movement will eliminate the mosquitos, The fish themselves will keep any other insects under control, I doubt I would add any more fish, If they have been in there for that many years and are doing good I would be afraid of disrupting the balance, 7' around isn't a lot of swimming area and I doubt that the fish are using the lower 10-15 feet of the well, the oxygen level and the pressure would be a lot for the Koi. Most koi prefer to use the upper 5-8 feet of water column

 

[Dave39]

Adding a air stone or water movement will eliminate the mosquitos, The fish themselves will keep any other insects under control, I doubt I would add any more fish, If they have been in there for that many years and are doing good I would be afraid of disrupting the balance, 7' around isn't a lot of swimming area and I doubt that the fish are using the lower 10-15 feet of the well, the oxygen level and the pressure would be a lot for the Koi. Most koi prefer to use the upper 5-8 feet of water column

Thanks for the input. I was concerned with the surface area not being enough for the fish despite how deep it goes.

 

[baeya]

The Koi must all be the same sex if there aren't any new Koi in there....or maybe the water is too cool for them to spawn.....don't know

 

[koiguy1969]

baeya....maybe they need a patio fireplace, wellside!

 

[addy1]

And someone cooking for them! How about one of those patio heaters, they throw a ton of heat!

 

[baeya]

LOL! And a little wine and cheese!

 

[Oldhead]

a small pump to keep the waters surface moving will get rid of the misquitoes..they like still or even stagnant water for egg laying. if this well is spring fed, and theres a constant input of fresh water it is possible that no filtration would be necessary...but mechanical removal of solids from the bottom woud beyond a doubt aid in maintaining water quality. you could hang planters from the well walls to give a little natural feel.

I like that planter hanging idea. I can do that with my pond.