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Pond Formulas
Here are a few simple formulas and conversions to help you plan your water garden. Formulas are approximate.
To Calculate Size of Pond Liner
Length = (Depth x 2) + Length + 3 feet
Width = (Depth x 2) + Width + 3 feet
Example: For a finished pond of 8' x 10' x 2.5', purchase a pond liner which measures at least 16' x 18'.
Length = (2.5 x 2) +10+3 feet = 18'
Width = (2.5 x 2) +8+3 feet = 16'
To Calculate Volume of Pond
(Use average measurements in feet)
Square or Rectangular shaped ponds
Length x Width x Depth x 7.48 = Pond Gallons
Example: 12' x 10' x 2' x 7.48= 1792.8 Gallons.
Circular shaped ponds
Radius= 1/2 of diameter
Area= Radius x Radius x 3.14
Volume= Area x Avg. depth x 7.5
To Figure Pump Requirements
Pumps should circulate the pond's water once every two hours at minimum. We recommend turning over the pond's volume once every hour.
Pond Volume / 2 = Pump Size
Example: 500 Gallon Pond /2 = 250 GPH Pump minimum.
Increase the pump requirement for water features such as fountains & water falls.
Tubing Flow Rates
| Max Flow (GPH) 320 720 1,200 3,000 4,800 6,000 9,000 12,000 |
I.D. of tubing 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" |
Max Flow (GPM) 5 12 20 50 80 100 150 200 |
To Figure Electrical Consumption
Amps X Volts (110 or 220) = Watts
Watts /1000 = Kilowatts
Example: PondMaster 250 pump
24 watts/hr x 24 hours/day = 576 watts/day
Divided by 1000 = .576 kilowatts per day
x 30 days/month= 17.28 Kilowats/month
@10 cents KWH x 17.82 = $1.73 per month elect. cost
Metric Conversions
1 Teaspoon : = 5 ml
1 Tablespoon = 15 ml
1 US Gallon = 3.78 liter
GPH = U.S. Gallons Per Hour GPM = U.S. Gallons Per Minute
