cooling down koi pond

[phillip]

hi, i have 4,500 gallon koi pond with a 1.2 metre sturgeon which is now suffering as water temp is 21-24 deg, well above 18 deg max for them

there is plenty of oxygen inputs (venturi and elctrical pump with stones) but ppm remains at 7-8 at this temp

any ideas (water chiller??) to cool down the pond?

thanks

[smaug]

What type sturgeon is it and what part of the world are you located.A chiller for a pond would be a major undertaking if done with a radiator or other heat transfer .I'm afraid that shading the pond is really the only good way.How many other fish and what species do you keep with the sturgeon?

[DrNic]

Different kinds of pond chillers are available. I've seen coil based units that hang into the water as well as pumps which circulate the water into the unit then expel cooler water out. I'm not sure which would be more effective in your case though. Check your local hardware store in the garden section where they keep the lawn stuff. That's where all the pond equipment is around here.

[jaysee]

It's going to cost A LOT to cool a pond that big. Are you taking the temp from the top of the pond or from the bottom?