Koi question please give me your opinion!

[Hellothere116]

So I'm located in the Cleveland Ohio area and if you don't know it gets pretty cold during the winter I have an above ground pond about a thousand gallons insulated bottom and insulated walls on the pond.
I have 10 koi anywhere from 5 in to 10 in in my basement right now since I just got them about 2 weeks ago.
My question really to all of you is what's your opinion on leaving koi outside during the winter?
I understand they should be fine but would you recommend it?
I filled the pond probably about 3 weeks ago and it had a steady temperature around 42°. I added a 300 watt heater for the heck of it so my filter and now it's consistently at 50° so I guess my last part to this post would be if I could keep it around 40° during the heart of the winter do you think I'll be okay just leaving them out there and of course not feeding them during that time.
Looking forward to all your opinions thank you very much!! Also I add some pics of the two bubo koi, I wouldn't mind hearing your opinions on their look as well thank you once again

 

[Fishman Dave]

I’m in the uk and mine are in the pond year round. 4000g with fish ranging from 8” to 28” and although it’s 6ft deep it often freezes over during winter. No issues. It’s more how quickly the temp fluctuates and if it’s insulated that should certainly help.

 

[duanes]

When I lived in WI, I had to bring my koi into a kiddy pool in an unheated basement from Dec to about March.
My ponds That were almost 4 ft deep, would freeze solid to the bottom

Temps in the basement in the dead of winter barely hit 50'F. I would stop feeding in Jan and Feb, when water temps hit their lowest

 

[gaxoo3]

Leaving koi outside during the winter can be a topic of debate among pond enthusiasts. While koi are known for their resilience in colder temperatures, it's important to consider a few factors before making a decision.

Firstly, the insulation and heating measures you have taken for your pond are commendable. Maintaining a stable water temperature is crucial for the well-being of koi during winter. However, it's important to note that extreme cold weather conditions, especially in Cleveland, Ohio, can pose challenges even with insulation and heating.

To ensure the safety of your koi, it's recommended to monitor weather forecasts closely. If there are prolonged periods of extremely low temperatures or severe weather conditions, it may be advisable to consider additional protective measures, such as using pond heaters or even temporarily moving your koi indoors.

Additionally, during the winter months, koi's metabolic rate slows down, and they enter a period of reduced activity. It's crucial to refrain from feeding them during this time, as their digestive systems become less efficient in colder temperatures.

Ultimately, the decision to leave your koi outside during winter should be based on careful consideration of local climate conditions, the effectiveness of your insulation and heating setup, and regular monitoring of your koi's well-being. Consulting with experienced koi keepers or local pond experts can provide valuable insights tailored to your specific location and circumstances.

 

[TheFishWorks]

As long as your water doesnt freeze any deeper than a thin top layer they should be fine. If the top freezes over its important to crack some open in order allow oxygen to flow through. As Gaxoo3 said above the big thing to remember is to slow/stop feeding during winter. If you do feed make sure its a low protein diet.

 

[jjohnwm]

I've read on numerous occasions that oxygen cannot dissolve into the water through a coating of ice. Seems reasonable, but fish can survive quite handily under even fairly thick ice as long as there is liquid water beneath. Can there possibly be so much dissolved oxygen in the water when it freezes in fall that the slower metabolism of the fish allows them to survive on this fixed supply until the spring thaw? Seems hard to believe...but the fish do survive, so...I dunno. If this is true, then obviously crowding or overstocking will be disastrous.

Water plants are a non-starter for winter ponds. They will die off and rot, albeit slowly, using up much of whatever oxygen does exist and resulting in fish deaths. Any plants should be in pots that can be removed before freeze-up.

Breaking the ice is a bad idea. I've broken it this way twice; on one occasion all the fish died within a day, and I lost most of them on the other occasion. I don't know if the shock waves are amplified under the ice or what the explanation is, but a hammer seems to be the wrong way to go about this task. If you feel you must expose the water surface, the safest way is by melting it open with hot water or a hot kettle or some other heat source.

Even if you do open the ice safely, it will quickly re-freeze again. You have two choices to keep the water open; the first is to use some kind of heater, such as a stock-tank heater as used by cattle farmers. These don't warm the water much, just enough to keep off the ice. If you are willing to pay the cost for electricity to heat an outdoor pond...more power to you. I guess the practicality of that idea depends upon how cold it gets and how reliable your power supply is; I know I ain't doing that!

The other option for maintaining open water is to use an aerator; the bubbles will keep the water surface from freezing directly above the air stone. But...they will also circulate the water, preventing the stratification that would normally keep a layer of slightly warmer water at the bottom. The ice remains open over the airstone...but it actually gets even thicker everywhere else as the entire water volume continues to cool beyond the point it normally would, and the fish are living in colder water than ever.

I made these observations while keeping natives in small outdoor ponds and containers, in southern Ontario. Those "ponds" were frozen over, sometimes many inches thick, for a couple months per year. I had no koi or goldfish, but the basic principles should transfer to those fish as well. In my current location, my one-and-only in-ground pond freezes solid right down the bottom, about four feet, and remains that way for several months each year. Container ponds like stock tanks would be destroyed by ice expansion; they must be drained and stored upside-down to survive the winter.

In my opinion, which is offered here for free and is worth exactly that cost...there will always be some risk in overwintering fish outdoors under ice...but the risk is minimized by just leaving the pond, the water and the fish alone. No hammering, no heating, no bubbling, no nothing. YMMV. Good luck and please keep us posted!

 

[tlindsey]

I know I ain't doing that!

 

[SilverArowanaBoi]

I think the Koi should be fine; Koi can handle temperatures down to 40 degrees. If it gets colder, I recommend bringing them into a warm indoor pool/pond until it warms up again. I know plenty of people who keep Koi, and one of my friend's husband kept his Koi throughout winter (though to be fair, it was in Louisiana, but it still froze), and they survived just fine.