What's the Minimum Temp for Koi?

[Russell Peters]

This corresponds to the lowest setting on my Thermostat or I would maintain 20C

That's the lowest temperature on my heater as well.

[vipldy]

Carl,if you wanna grow them 70's would be good!

[Carl]

Solar. Run pond water through long black pipes exposed to sunlight. You can cover one side of a barn roof with a grid of black pipe and get good results. Not sure you can get to 50, but a 10 or 15 degree increase in normal temp is likely.

Brad

Wouldn't you want to bypass that at night, though? If not, wouldn't it act to cool the water at night?

[CHICHI]

Wouldn't you want to bypass that at night, though? If not, wouldn't it act to cool the water at night?

In General

[six6guy]

Wouldn't you want to bypass that at night, though? If not, wouldn't it act to cool the water at night?

Yes. My brother has this setup, he is in the central Washington hills (Wenatchee area). We just setup a 100vac timer to control the pump, he adjusts the timer to match sunlight hours. It works pretty good.

Brad

[stephen]

I don't want then to grow until they are outside in the spring.

No reason to let it get below 50 except for the cost.

[vipldy]

I would say 50-55 then but more like 55

[six6guy]

That's the lowest temperature on my heater as well.

I have the heater units from a king sized water bed under my intex QT. So I only have low, medium, and high (and every possible position in between). So low is as low as I go.

Brad

[madeyna]

Just though I would mention that my koi thawed out and are swimming around in the ice. I am thinking about putting them in the big pond since temp. swings would be less in the 5000 gallon in the ground. They just froze over in the stock tank and that cann,t be good. I am not sure the stock heater would maintain 50 and above though.

[Cowiche Ponder]

Yes. My brother has this setup, he is in the central Washington hills (Wenatchee area). We just setup a 100vac timer to control the pump, he adjusts the timer to match sunlight hours. It works pretty good.

Brad

Brad he has to be using it as a heat exchanger with something other than water in the pipes or the water would freeze at night, or the whole thing would have to be set to drain completely

[Graham]

The big problem that I can see with solar heating pipes is the big swing that could occur from day to night, let alone the swing based on ambient air temps. If there was some way to use an auto thermostat to control a pump gph then it might work.

I know that the ambient air temps in the koi house can go from 50* to 90* in 24 hours; taking tank temps up or down by about 7*> 8* in the process. I can't imagine what solar pipes might do depending on the day and where you live.

I like when it goes up in temp, then the heaters don't kick in. They're set at a minimium of 58*

G