The Pond Pump and Liner Plan

A new garden pond worked from the numbers that matter: a liner sized on the deepest point and rounded up to a sheet you can buy, the gallons counted on fill day, and a pump read on its chart at your pond's head, with the pipe that keeps the power bill down

Our Filter Turnover Calculator gives the flow a pond needs, but a pump box quotes its flow with no lift and no pipe. Our Pond Volume Calculator wants the average depth while the Pond Liner Calculator wants the deepest point, and typed the wrong way round an example kidney pond reads 1,615.79 gallons where it holds 942.55, 71% more water than is there. The Pond Pump and Liner Plan carries the three tools through a build. In the worked example the liner comes to 20 x 16 ft and is bought as 20 x 20, because the nearest stock size leaves 6 inches at the long edges; the hose counts 915 gallons on fill day; and a pump sold as 700 GPH delivers 329.63 GPH through thin pipe, a 2.78 hour turnover where 2 was the plan. A wider pipe lets that same small pump meet the 457.5 GPH target for $96.80 a year less to run than the pump the thin pipe needs. Every figure is computed by the code behind our calculators, and every pond, pump curve and price is an example for you to replace. It adds the safety facts a build needs: RCD or GFCI protection and a qualified electrician for the pump, and children kept from the water with a grille, a locked fence or no pond yet. It covers no salt, medicine or water treatment, and gives no structural advice. Inside: seven steps, four printable working pages, friction and pond reference tables and a quickstart, plus a personalised sheet worked from the numbers you enter in our calculators.

Look inside

Two full pages from the plan, exactly as printed. Click either to read it at full size before you decide.

What is in it

• The Two Depths Rule: the deepest point for the liner, the average depth for the water
• The Round Up Rule: the liner with the overlap at both edges, rounded up to a stock sheet, and the dug hole taped before ordering
• The Fill Count Rule: the pond's real gallons from a timed hose or a water meter, and fish worked on that count
• The Delivered Flow Rule: a turnover target for koi, goldfish or plants, as flow delivered at your head
• The Lift Plus Friction Rule: total head from the lift, the pipe run and its elbows, for four pipe sizes
• The Curve Rule: each pump read on its chart at your head, and pipe and pump pairs priced by their yearly power bill
• The Safe Start Rule: RCD or GFCI protection, a qualified electrician, children and water, and a bucket test at the outlet
• Four printable working pages: hole and liner sheet, fill count sheet, head sheet, pump and power sheet
• A pipe friction table for six flows and five pipe sizes, six example ponds with liners and flows, and a units table
• A quickstart checklist and a personalised sheet worked from your own calculator inputs

The plan picks up where the free Filter Turnover Calculatorleaves off. That calculator gives the flow your pond needs, but a pump's box figure is its flow with no lift and no pipe; the Pond Volume Calculator wants the average depth while the Pond Liner Calculatorwants the deepest point. The plan carries them through: two depths for two jobs, a liner rounded up to a sheet you can buy, the gallons counted on fill day, a turnover target, the head your plumbing adds, the pump read on its curve with the pipe that keeps the power bill down, and power and children's safety before the fish go in. Every figure in it is an example for you to replace. It covers no salt, medicine or water treatment of any kind: if fish are sick, ask an aquatic veterinarian.