Water Gardening & Fishing: What Great Combination!

# 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

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