I have read about using a small dorm size fridge and converting it to
cool the water in the pond.

You can forget that, it will be a complete waste of labor.

I would like to hear from other AZ ponders
and know if you all are doing anything for cooling your pond temps.

http://www.aquaticeco.com/index.cfm/...ories/ssid/370

That will work if it's big enough. Keep in mind that /most/ of these units
are designed for home aquariums, and most home aquariums aren't 700 gallons.
OTOH, if one wants to take a pond from 90 to say 78 or so, a smaller one might
do it. I think one should probably do the math on the unit.

Now, before you go off and stock your pond with expensive koi that you fall
in love with, consider the consiquence if this chiller fails. At 90 degrees,
your koi will probably die.

I think you need to not have to worry about a critical failure here.

Deep pond, some shade. That's a good "plan A".

C//