The Pool Running Cost Plan

A pool pump and heater worked from your own numbers: the head read off your gauges, the flow read off the pump's curve instead of its box, the slowest speed that still turns the water over, and a season's running and heating bill at your rate

Our Pump Turnover Calculator takes your pump's flow and notes, in its own words, that real flow is lower because of plumbing head loss and a dirty filter. It cannot say how much lower, and the biggest number on a pump's box is its flow at zero head, where no pool pump works. The Pool Running Cost Plan works it out on your pool. In the worked example, a 19,150 gallon pool needs 39.9 GPM to turn over in 8 hours; its gauges read 46.1 ft of head, where a pump sold as 110 GPM delivers 71.46, so a turnover takes 4.5 hours, not 3. A bigger pump costs $37.50 more a season and pushes past the filter's 80 GPM rating, while a variable-speed pump at 51% clears the target for $55.50 a season instead of $217.50, as long as the filter is clean: loaded to 26 psi, the same speed falls to 24.31 GPM. The heater's 1,916,532 BTU are priced by fuel, beside an overnight cover test you run yourself. Every figure is computed by the code behind our calculators, and every pool, pump curve, price and reading is an example for you to replace; low-speed watts are ideal figures your pump's display replaces. It covers no pool chemicals. It carries the safety a pool's equipment and ownership need: GFCI protection and an electrician qualified in pool and spa work, drain covers, a four-sided fence with a self-closing, self-latching gate, a Water Watcher, and heated water at or below 104 F. Inside: seven steps, four printable working pages, 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 Target Flow Rule: your gallons worked once, and the flow that turns them over in your run window
• The Gauge Rule: total head from your filter pressure and suction gauges, clean and before cleaning
• The Curve Rule: the flow read off the pump's curve at your head, three pumps compared, and the filter's maximum flow
• The Kilowatt-Hour Rule: hours, kWh, a day and a season at your own electricity rate
• The Square Rule: the slowest variable speed that still clears the target, and what a loaded filter does to it
• The Cover Test Rule: the heat-up priced by gas, heat pump or electric, and the overnight drop measured cover off and on
• The Safe Water Rule: GFCI and a qualified electrician, drain covers, a four-sided fence and gate, a Water Watcher, and a season budget
• Four printable working pages: pool and gauge sheet, curve sheet, run plan and bill sheet, heat and cover log
• Reference tables: turnover hours for six volumes and six flows, gauge to feet of head, speed and energy, and units
• A quickstart checklist and a personalised sheet worked from your own calculator inputs

The plan picks up where the free Pump Turnover Calculatorleaves off. The calculator relates your gallons, a pump's flow and the turnover time, and notes that real flow is lower than a pump's rating. The plan works out how much lower on your pool: the head read off your own filter and suction gauges, the flow read off the pump's curve, the hours and the bill at your electricity rate, the slowest speed that still clears your target, and why a loaded filter undoes it. It uses the Pool Volume Calculator for the gallons and the Pool Heater BTU Calculator for the heat-up, priced by fuel, beside an overnight cover test you run yourself. Every pool, pump, price and reading in it is an example. It covers no pool chemicals, and it carries the equipment and water safety a pool needs: GFCI protection and a qualified electrician, drain covers, a four-sided fence with a self-closing, self-latching gate, and a Water Watcher. No saving is promised.