Water Temp for Koi in outdoor pond

[retiredusaf]

Does anyone know what the maximum temperature for outdoor pond water that Koi fish can withstand. We have had a heat wave here in Arlington, TX, for several weeks. Since Aug 1, 2010, it has been over 100 degrees everyday except 1 day. Yesterday, 08.23.2010, we tied a record temp for the date at 107 degrees. My biggest Koi, about 12" died, I'm guessing, of heat related stress. The 14 other smaller Koi seem to be okay. I test the water weekly at it is always perfect. The water temp was about 92 degrees. So, I may have answered my own question, 92 degrees might be the maxium. We get a break in the weather today, only 99-100 and then forecast is for cooler weather finally. Predicted to be in low to middle 90's until end of Aug with lows as low as 72. Anyway, I found the Koi laying on the bottom almost dead. Tried to put it in a separate tank with a little cooler water for about an hour. It seemed to recover somewhat but after I put him back in the pond near the waterfall he died within an hour. When the water gets extremely hot is there anything I can do to help the fish? I planted a Yaupon Tree to provide some shade and there are ledges and rock covered areas to hide in and possible get more shade. The pond is 2 1/2' deep.

Thanks for your comments.

 

[RSFish1]

How much water movement do you have? The hotter the water the less oxygen it can hold. It would not hurt to add aeration either through an air pump or splashing the water more. I keep a pump shooting up from the bottom of my pond and churning the water so that it splashes and adds as much oxygen to the water as possible.
Watch the other fish and see if they are hanging out more around your waterfall where the oxygen is probably the highest. Watch for the tell-tale signs of them at the surface mouthing for air.
I am sure someone will come along about the temperatures. But it may be a situation of cause and effect.

 

[hewhoisatpeace]

I'll second RSFish. Oxygen dissolves mu better in cooler water, I'd certainly add an airatone or two.

My pond, in SC, maxed out at 90 on two days this past summer, but I have little shade yet. No ill effects for the fish.

 

[bsr8129]

im sure my pond water is up there, we have been having a heat wave here, plenty of aeration is the key

 

[DrDave]

What he said...

 

[Sojourner]

I live in south Florida, the temps have been in the 90's. My pond is partly shaded. I use a seneye to monitor my system. My water temperatures have been hovering around 82 degrees, I've lost several fish. I have the water fall running 24/7 and aeration. I know dissolved oxygen drops as water temps increase. I have been considering getting a water chiller to reduce the pond temp (slowly). Has any one had any experience with this? I have a 3300 gallon pond.

 

[mrsclem]

Welcome Sojourner! This thread is 8 years old. How about posting an intro and telling us all about your pond. And please post pictures!

 

[carolinaguy]

The max temp for koi is the same as any fish and is based on the physical chemistry of water. The oxygen saturation curve can be found on line. At about 5 percent oxygen saturation, koi can’t exchange oxygen fast enough, and that number is the start of a fish kill just like you will find on a lake. I think the 5 percent point is about 96 degrees but that number does not consider a fish with compromised gills. Best to shade your pond with a sail or umbrella. Some add dye to the water or have floating plants that help. In the extreme some toss bags of ice in to drop the temperature. A fountain spray might help. Not sure if that evaporation will counter heating water with 110 plus degree air.

 

[sissy]

old post but sojourner do you have an aerator

 

[Sojourner]

I'll post on a new thread soon thank you : )

 

[sissy]

I know mine is around 82 after all the rain we have had