2026-27 rates are live. DMO, VDO and solar feed-in tariffs updated for July 2026. See what changed

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Fish Tank Running Costs for Cold Water and Tropical Tanks

An aquarium runs all day, every day. Here is what that costs on 2026-27 electricity prices and where the power goes.

Checked against regulator sources, October 2026

Typical draw
80 W
Medium tropical tank
Usage assumed
701 kWh
a year
NSW cost
$232
a year, Ausgrid
Cost an hour
3c
NSW reference rate
watts
hrs
days

Use decimals for short times. 15 minutes is 0.25 hours.

State or territory

Fish tank: cost a year

$232

2.7c an hour63.6c a day$4.45 a week$19.35 a month
Energy usedper year701 kWh
Electricity priceAusgrid, flat rate33.14c
Share of a typical homeagainst 4,000 kWh a year18%
Cost a year, GST included$232.23

Appliances on a thermostat cycle on and off, so real use is often lower than the full power draw.

Prices are 2026-27 regulated rates including GST. Market offers can be cheaper. Estimates only.

What a fish tank costs to run in each state

The table assumes a medium tropical tank with an average draw of 80 W around the clock.

Fish tank: medium tropical tank, 24 hours a day, every day
StateRateA monthA year
TasmaniaAurora Energy24.75c$14.45$173
QueenslandEnergex27.97c$16.34$196
Victoriaaverage of five networks28.2c$16.47$198
Northern TerritoryJacana Energy31.68c$18.50$222
New South WalesAusgrid33.14c$19.35$232
Western AustraliaSynergy33.26c$19.43$233
Australian Capital TerritoryEvoenergy network36.95c$21.58$259
South AustraliaSA Power Networks41.91c$24.48$294
Flat regulated usage rate for each state's main network in 2026-27, including GST. Victoria uses the average of its five networks.

Running costs by tank set-up

Running costs by type, 24 hours a day, every day
TypePowerCost an hourA year
Small cold water tank, filter and light15 W0.5c$44
Medium tropical tank80 W3c$232
Large tropical tank200 W7c$581
Priced at the Ausgrid reference rate of 33.14c/kWh. Use the calculator for your own state and hours.
Where a tropical tank's power goes
EquipmentTypical ratingRuns
Heater50-300 W, sized to the tankOn and off by thermostat
Filter5-30 W24 hours a day
LED light10-40 W8 to 10 hours a day
Air pump2-5 W24 hours a day
Typical equipment ratings. Check the labels on your own equipment.

How to cut tank running costs

  1. Insulate the back and sides

    A sheet of foam board behind the tank keeps heat in, so the heater runs less.

  2. Use a lid

    A lid cuts heat loss and evaporation.

  3. Put the light on a timer

    Eight to ten hours of light suits most tanks and avoids lights running all night.

  4. Keep the tank away from windows and draughts

    A cold spot makes the heater work harder in winter.

Measure it

A plug-in power meter on the power board shows what the whole tank really uses over a week. See our measuring energy use guide.

Questions about fish tank running costs

A medium tropical tank averaging 80 W costs around $19 a month on the Ausgrid reference rate. A small cold water tank costs about $4 a month.

Usually the heater in a tropical tank. Large lights on marine and planted tanks can also draw a lot.

Keep a lid on, insulate the back and sides, keep the tank away from cold windows and draughts, and use a correctly sized heater with a good thermostat.

Sources

Every rate on this page comes from the regulator or the regulated retailer. Last checked October 2026. Prices include GST unless we say otherwise.