This pages contains information that may be of use in planning pond activities and projects in North Texas.

 

 

 

 

 

 

 

 

 

 

                  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 5.30 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 79°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)

USDA Hardiness Zones

Many of us live in zones 7B or 8A.  The border between those zones a diagonal line from the northern Dallas suburbs (i.e., Plano) to the south side of Ft. Worth.  Downtown Dallas is Zone 7b.  Downtown Ft. Worth is Zone 8a. 

  Zone     Fahrenheit       Celsius       Example Cities  
1  Below -50 F   Below -45.6 C Fairbanks, Alaska; Resolute,    Northwest Territories (Canada) 
2a -50 to -45 F   -42.8 to -45.5 C Prudhoe Bay, Alaska;                       Flin Flon, Manitoba (Canada) 
2b -45 to -40 F -40.0 to -42.7 C Unalakleet, Alaska;                  Pinecreek, Minnesota 
3a -40 to -35 F -37.3 to -39.9 C International Falls, Minnesota;             St. Michael, Alaska
3b -35 to -30 F -34.5 to -37.2 C Tomahawk, Wisconsin;                 Sidney, Montana
4a -30 to -25 F -31.7 to -34.4 C Minneapolis/St.Paul, Minnesota;            Lewistown, Montana
4b -25 to -20 F -28.9 to -31.6 C Northwood, Iowa;                       Nebraska
5a -20 to -15 F -26.2 to -28.8 C Des Moines, Iowa;                             Illinois
5b -15 to -10 F -23.4 to -26.1 C Columbia, Missouri;                  Mansfield, Pennsylvania
6a -10 to -5 F -20.6 to -23.3 C St. Louis, Missouri;                    Lebanon, Pennsylvania
6b -5 to 0 F   -17.8 to -20.5 C McMinnville, Tennessee;             Branson, Missouri 
7a 0 to 5 F -15.0 to -17.7 C Oklahoma City, Oklahoma;             South Boston, Virginia
7b 5 to 10 F -12.3 to -14.9 C Little Rock, Arkansas;                   Griffin, Georgia
8a  10 to 15 F -9.5 to -12.2 C Tifton, Georgia;                            Dallas, Texas 
8b 15 to 20 F -6.7 to -9.4 C Austin, Texas;                        Gainesville, Florida
9a 20 to 25 F -3.9 to -6.6 C Houston,Texas;                                 St. Augustine, Florida
9b 25 to 30 F -1.2 to -3.8 C Brownsville,Texas;                              Fort Pierce, Florida
10a 30 to 35 F 1.6 to -1.1 C Naples, Florida;                         Victorville, California
10b 35 to 40 F 4.4 to 1.7 C Miami,Florida;                                Coral Gables, Florida
11 above 40 F above 4.5 C Honolulu, Hawaii;                        Mazatlan, Mexico

Temperature Conversion  (Fahrenheit - Celsius)

TEMPERATURE CONVERSION

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:

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

The example covered pond in Option B above needs a heat exchanger capable of 5,670 BTU/hr.  The properly sized electric heater would be 2KW.  That will a moderate system to run.

Water Quality

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 is it is inexpensive.