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Tuesday, June 18, 2013
 
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Dallas - Ft. Worth Area Monthly Weather Averages

Month Avg. High Avg. Low Mean Avg. Precip. Record High Record Low
Jan 55°F 36°F 46°F 1.89 in. 95°F (1911) 2°F (1949)
Feb 61°F 41°F 51°F 2.31 in. 95°F (1996) 2°F (1910)
Mar 69°F 49°F 59°F 3.13 in. 98°F (1911) 12°F (1948)
Apr 77°F 56°F 66°F 3.46 in. 99°F (1963) 29°F (1914)
May 84°F 65°F 74°F 5.60 in. 103°F (1911) 36°F (1903)
Jun 92°F 73°F 82°F 3.92 in. 112°F (1980) 48°F (1903)
Jul 96°F 77°F 86°F 2.43 in. 111°F (1954) 57°F (1905)
Aug 96°F 76°F 86°F 2.17 in. 115°F (1909) 55°F (1906)
Sep 89°F 69°F 79°F 2.65 in. 107°F (1913) 40°F (1908)
Oct 78°F 58°F 68°F 4.65 in. 100°F (1979) 26°F (1910)
Nov 66°F 47°F 56°F 2.61 in. 92°F (1910) 15°F (1911)
Dec 57°F 39°F 48°F 2.53 in. 89°F (1955) 1°F (1989)

 


Calculating Pond Volume

It is vital to know the volume of your pond in gallons in order to properly size pumps, filters and dispense pond chemicals. Pond volume in gallons can be initially calculated from the following: pond length (in feet) times the pond width (in feet) times the pond depth (in feet) times 7.48 (gallons in a cubic foot).

Geometric shapes are simple to calculate, i.e., squares and rectangles. The gallons of a round pond can be obtained from: pond radius (in feet) times the pond radius (in feet) times Pi (3.1415) times the pond depth (in feet) times 7.48 (gallons per cubic foot) .

Many garden ponds are free form in shape. The gallons of these ponds can be estimated by dividing the pond surface into several more familiar geometric shapes, i.e., squares and circles, calculating the gallons of each section and then summing the gallons of all sections.

Example: Our pond is 16 X 8 X 4.5 deep. So the surface area is 16 X 8 = 128 square feet. 128 square feet X 4.5 of depth = 576 cubic feet. 576 cubic feet X 7.48 = 4,308.48 gallons of capacity in the pond.

Remember that the approach will give you an estimate of the pond volume. It will not include the water in your filters, plumbing lines, waterfalls, other other areas. To accurately determine the total system volume, fill the pond using a water meter. You can use the water meter on your house to do this. Note the meter reading before starting and when the pond system is full. Please do not operate clothes washing machines, dish washers, and other devices that use a significant amount of water while the pond is being filled.

 

Calculating Pond Heater Size in BTU/hr:

Option A for Heat loss calculation for uncovered pond:

Heat loss (Btu/hr) = 12 X pond surface area X desired pond temperature - coldest ambient temp.

Example: Pond is 9 feet wide and fifteen feet long, uncovered surface. I want the pond around 70F and it gets down to 28F at night. Sometimes colder, sometimes warmer. Here's the math: 12 X (9ft x 15ft) X [70F minus 28F at night]. Works out to: 12 X 135 sq. ft. X 42F margins. = 68,040 BTU/hr.

Option B for Heat loss calculation for almost completely covered pond:

Heat loss (Btu/hr) = pond surface area X desired pond temp. - coldest ambient temp. Make sure an airspace is maintained between the surface of the pond and the cover. Do not float the cover directly on the pond.

Example: Pond is 9 feet wide and fifteen feet long, with a covered surface. I want the pond around 70F and it gets down to 28F at night. Sometimes colder, sometimes warmer. Here's the math: (9ft X 15ft) X [70F minus 28F at night]. Works out to: 135 sq. ft. X 42F margins. = 5,670 BTU/hr.

 

Calculating Pond Heater Size in Kilowatts:

* First do the calculations to determine the BTU/hr needed for your uncovered or covered pond.

* Divide the BTU/hr calculation result by 3,412. This will tell you the size of electric heater needed in kilowatts (KW).

In the previous example for an uncovered pond in "Option A", it will need a heat exchanger capable of 68,040 BTU/hr. The properly sized electric heater would be 20KW. That will be a very expensive system to install and operate, given the price of large electric heaters and the quantity of electricity to power them! So it you are planning to heat the pond, plan on some type of cover!

The previous example of a covered pond in "Option B" needs a heat exchanger capable of 5,670 BTU/hr. The properly sized electric heater would be 2KW, 90% smaller than the size needed for the uncovered pond. That will be a much more economical system to run.
 

Water Quality

* If you have well water: You should not need to use a dechlorinator. Check your water to be sure! Well water has its own set of problems.

* If your water is treated with chlorine (ask your local government): You will need to use a dechlorinator. Some products remove both chlorine and chloramines.

* If your water is treated with chloramines (ask your local government): Cloramine is the combination of chlorine and ammonia. When you use a dechlorinator the chlorine is neutralized instantly, but the ammonia is left. Some products remove both chlorine and chloramines. A good filter system will also help remove this ammonia in a few hours just as it does the ammonia generated by the fish.

* If you do not have a stable colony of filter bacteria (i.e., new pond, cold weather) or you are adding a large quantity of water (over 25% of the pond capacity) consider a commercial dechlorinator that also renders the ammonia harmless to fish. Amquel and Chloram-x are just two examples of these kinds of products.
 

Electronic Scale

If you need to measure grams of pond chemicals or medicines, such as Potassium Permanganate, what do you use? You drive to your local Wal-Mart or kitchen store such as Sur La Table or go to a web site such as: 
 http://www.chefsresource.com/tools-kitchen-scales.html.

The scale will measure in grams or pounds plus ounces. Some will measure up to 5 pounds. Be sure to wash the measuring tray between uses to avoid mixing chemicals.
 

Increase the Pond Calcium Carbonate Level

To increase the calcium carbonate level of your pond follow the approach used by the Japanese Koi breeders. Head to your local feed and seed store. Purchase a bag of powered or crushed oyster shells. The oyster shells are mixed into the chicken's food to promote strong egg shells. Put the oyster shells into a mesh bag and put the bag somewhere in the filter system. Use one pound of oyster shell for each 1 thousand gallons of pond water. The shells will slow dissolve and help prevent a pH crash. The best part is the cost because it's inexpensive.