Pond Boss Forums INTRO Questions & Observations Overwintering talpia

Ok, I'll take a stab at the Math and clearer minds can pick these figures to pieces. I'm using data from How Many Gallons is My Pond?

Worst case, 1/2 acre at 5 feet = 2.5 acre-feet

2.5 acre-feet X 43,560 ft2/acre = 108,900 cubic feet

108,900 ft3 X 7.5 gallons/ft3 = 816,750 gallons

Best Case = 1/4 acre, cut it all in half.

----------------------------------------

Let's say 400,000 gallons best case, 800,000 gallons worst case. At 45 degrees.

----------------------------------------

Now, you pump 100 gpm 24/7. That's 6000 gpHour, which makes 144,000 gallons per day. At 67 degrees.

For the simplest possible "Mix the water and warm the pond" model, adding 144k gallons at 67 degrees to 400k gallons at 45 degrees would give 544k gallons at

[(144k X 67) + (400k X 45)]/544k = 50.8 degrees, IF the water was added and mixed instantaneously (you would need a really good spillway or drain in this case )

Worst case, the simplified model raised temp would be

[(144k X 67) + (800k X 45)]/944k = 48.4 degrees

----------------------------------------

Now, how bad an estimate of raising temperature is the simplified, mix-it-all-at-once model above?

I believe that the temps predicted above are an upper limit that will not be met in reality. This is due to the fact that since the warm water is added over a 24 hour period, instead of instantaneously, the cold Winter (air) temperatures will be lowering the temperature of the well water after it enters the pond and before all 144,00 gallons of it can warm the pond up to the above temps (50.8 or 48.4 degrees). My brain is not working well enough to explain this prediction better right now, but the effect has matched experimental results I have obtained pumping cool water into warm water while heating the overall mixture, albeit in the opposite direction (cooling versus warming).

I would be very interested in Cecil or another high-volume well/small pond 24/7 pumper making a prediction of what your upper well-warmed pond temp might be, and would place a greater emphasis on a good estimate based on real-life, real-pond experience than on my theoretical projection shown above.