What a Pool Pump Actually Does

A pool pump draws water from the pool through the skimmer and main drain, pushes it through the filter, and returns it to the pool through the return jets. This continuous circulation keeps the water clean — without it, the water stagnates, chemicals don't distribute evenly, and debris isn't captured by the filter.

The pump must circulate the entire pool volume through the filter at least once every 24 hours (the minimum). During summer, twice-daily turnover is recommended for North Brisbane pools. The rate at which the pump achieves this is called the turnover rate.

Single Speed vs Variable Speed Pumps

Single speed pumps

Run at one fixed speed — typically around 2,850 rpm. They're simpler, cheaper to buy, and have been the industry standard for decades. The downside: they run at full power regardless of what the pool needs, which means consistently high energy consumption.

Variable speed pumps (VSP)

Can run at different speeds depending on what's needed. During normal filtration, they run at a low speed — often using 70–80% less energy than a single speed pump. They ramp up when needed for backwashing or operating water features.

VSPs cost more upfront ($1,200–$2,500+ installed vs $600–$1,200 for single speed) but typically pay back the difference in electricity savings within two to three years. For a pool running 8+ hours per day, the annual saving can be $600–$1,200 in electricity.

For most North Brisbane pool owners, a variable speed pump is the recommended default — particularly given Queensland's high electricity prices and year-round pool use.

How to Size Your Pump Correctly

Pump sizing is calculated based on your pool volume and how quickly you want to turn the water over. The formula:

Pool volume (litres) ÷ Turnover time (hours) = Required flow rate (litres per hour)

For example: A 50,000-litre pool targeting an 8-hour turnover needs at least 6,250 litres per hour. But flow rate alone isn't enough — you also need to factor in the resistance in your plumbing system. Larger pipe diameter, shorter runs and fewer bends all reduce resistance and allow a smaller pump to do the same job.

Oversizing is also a problem. A pump too large for your system creates excessive pressure, reduces filter efficiency and wastes energy. If you're replacing a pump, have a professional assess your system before selecting a replacement.

Energy Efficiency and Running Costs

In Queensland, electricity costs approximately $0.30–$0.35 per kWh. A 750-watt single speed pump running 10 hours per day uses 7.5 kWh — about $2.50/day, or $900/year. The same circulation duty on a variable speed pump at 300 watts uses 3 kWh — about $1.05/day, or $375/year. Over five years: a saving of around $2,600 — more than enough to cover the premium cost of a VSP.

When comparing pumps, look at minimum operating wattage (not just maximum), energy rating, and the manufacturer's recommended operating range for your pool size.

Signs Your Pump Needs Replacing

• Unusual noise — grinding, rattling or humming suggests bearing wear or debris in the impeller

• Reduced flow — visible as weak return jets or slower water turnover

• Pump struggling to prime — often a seal issue or air leak

• Tripping the circuit breaker — may indicate an electrical fault or motor overheating

• Visible leaking from the pump body — seal or o-ring failure

Most pumps last 8–12 years with proper maintenance. If yours is over 10 years old and showing any of the above signs, get an assessment — repairing a pump at this age often costs more than a new pump.

What to Look for When Buying

• Correct flow rate for your pool volume and turnover goal

• Variable speed if budget allows — the energy savings justify the cost for year-round Queensland use

• Known brand with available parts and local service support (Davey, Pentair, Hayward, Astral, Zodiac)

• Minimum 2-year warranty on pump body and motor

• Noise level if the pump is near living areas — VSPs are significantly quieter at low speeds

Pool pump replacement in Queensland involves electrical work. Under Queensland regulations, the electrical connection must be carried out by a licensed electrician. At Atlantis Pool Services, we supply and install pool pumps with all electrical and plumbing work covered. Call (07) 3491 9700 or visit our North Lakes shop.