Pond Boss Forums Thread Like Summary - MO question via email

Here is the question I received by email - assume it came from a viewer on PB. You guys take a shot at answering the question.

Question -

I'm in Southern Missouri you have any idea how deep a hole it would take to have a temp of 65 degrees, our summers are brutal into the 90 degree temps. Im debating using aeriation kit at 10' depth when temps drop down at night. I have no idea where the thermocline depth is here.

This is an example of "I don't know what I don't know" situation.

Lacking knowledge and experience, it is impossible to ask good questions, so you just have to start where you are and go from there.

I was the poster boy for topical ignorance when I started my pond renovation. If I hadn't found the PB forum I would have a leaky hole
full of boring fish in my front yard.

Best advice I could give to the person who posed the original question would be to read every single post in the archive. I did that very
thing after I discovered this place. By doing so, I cured my ignorance. Many of the questions that I didn't know I had were answered
before I ever had to ask them, and I had put myself in a position where I knew *just enough* to ask a sensible question, and make sense
of the answers that were given.

ewest,

There are many good maps available of ground temperatures. Basically, in most places the heat flow flux from the center of the earth is so small that once you get deeper than 10', the ground temperature is a very close approximation of the integral of the air temperatures over the course of the "average" year.

Below is a link from the heat pump guys. Their calculations require a fairly accurate estimate of your groundwater temperature.

https://assets.supply.com/ul_pdfs/284997_GroundWaterTemperatureMap.pdf

The ground temperature sets the lower limit for his "average" water temperature below the pond's thermocline. (Obviously, he will start with colder bottom water coming out of winter.)

After that, the calculations get very complicated very quickly. However, circulating water is very efficient at equalizing its temperature. Once he starts aerating from below his thermocline, he will lose his pool of cool water pretty quickly.

I don't see any possible way he could have an entire pond with 65 degree water with prolonged exposure to 90 degree air during the day and 70 degree air at night. (If that is his desire.)

The only exception would be having a deep, still quarry right beside his 2 acre pond. You could then pull cold bottom water for the duration of the summer and make it work.

I have been trout fishing around Atlanta, Georgia. Some of the spillways at the huge reservoirs have bottom drains that provide the only release water during periods with low lake levels. There are trout farms that exist just below the spillway outlets and can pull in this 60 degree water. That is the only way to make the physics work if I am understanding the email question correctly.

Rod