Small Water Tanks | <6,000L

Compact Promax water tanks in capacities from 120L to 5,000L. The range includes ENDURO with corrugated walls (450L to 5,000L) and XPRESS with smooth walls (2,500L to 3,500L) for residential homes, small farms, and commercial sites. All tanks are manufactured from polyethylene by rotational moulding. 5-year pro-rata warranty.

Rainwater harvesting, backup water supply, garden irrigation: a small tank handles everyday needs without a large investment. For larger capacities (10,000L and above), see the Large Water Tanks collection.

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3,500L Water Tank - XPRESS

$1,196.00

2,500L Water Tank - XPRESS

$968.00

5,000L Water Tank - ENDURO Low Profile

$2,562.00

4,000L Water Tank - ENDURO

$1,614.00

3,000L Water Tank - ENDURO

$1,370.00

2,000L Water Tank - ENDURO

$1,163.00

1,000L Water Tank - ENDURO

$879.00

450L Water Tank - ENDURO

$509.00

5,760L Water Tank - XPRESS

P.O.A

120L Water Tank

$507.00

5,000L Industrial Tank - ENDURO in Mist Green

5,000L Water Tank - ENDURO

$1,925.00

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Why You Need a Small Water Tank

Not every property needs a 25,000L tank. On urban sites with limited space, where the need is for irrigation, laundry, and toilets, a plastic water tank of 2,000L to 5,000L is sufficient. For a bach or small garden, 450L to 1,000L is enough. For technical purposes (collecting condensate, equipment washdown), even 120L will do.

In Auckland, Wellington, and other cities, councils periodically impose restrictions on mains water use. Your own polyethylene rainwater collection tank provides an independent source that refills every time it rains.

On small farms and lifestyle blocks, a 3,000L to 5,000L tank provides water for stock and irrigation. A typical setup: a pump delivers water to a tank at a high point on the property, from where it flows by gravity to troughs.

When a small water tank is needed:

Urban site with limited space
Rainwater collection for irrigation, laundry, or toilets
Council has imposed mains water restrictions
Small farm or lifestyle block needs independent water supply
Compact tank for technical purposes

When a Small Water Tank Is Needed:

On an urban site, rainwater replaces mains water for irrigation, laundry, and toilet flushing. The tank fills for free when it rains and reduces your water bill. A significant portion of household water goes to toilets and irrigation, and rainwater replaces mains for these purposes entirely. Even a 2,000L tank noticeably reduces mains consumption. In areas with water metering, which is being progressively introduced across New Zealand, the savings become even more significant.

On a small farm or lifestyle block, your own water reserve means confidence in tomorrow. When the council restricts supply, when a main bursts, when a drought drags on, the tank provides water regardless of external circumstances.

A Promax polyethylene tank requires no maintenance. The material does not rust, does not react with water, and does not degrade over time. 5-year pro-rata warranty: the manufacturer takes responsibility for durability over the full term.

What Capacity to Choose

The right capacity depends on intended use and the number of people.

120L: technical purposes, washdown, condensate collection
450L to 1,000L: watering a small garden, bach, single person
2,000L to 3,000L: household needs for a small home (toilet, laundry, irrigation)
4,000L to 5,000L: full household use for a family of 3 to 5, or a small farm

For exact capacity calculations, Promax provides technical support. If one tank is not enough, multiple tanks can be connected in parallel using a Tank Balancing Kit.

ENDURO series: 450L to 5,000L

The corrugated walls of the ENDURO provide increased strength and rigidity. On a narrow urban site, the compact dimensions allow placement along a fence or house wall.

Available capacities: 450L, 1,000L, 2,000L, 3,000L, 4,000L, 5,000L.

ENDURO tanks can be partially buried to one-third of the tank height without voiding the warranty. This reduces the visible height and simplifies connection to gravity-fed systems.

XPRESS series: 2,500L to 3,500L

The smooth walls of the XPRESS simplify installation of level indicators and pumping equipment.

Available capacities: 2,500L, 3,500L.

XPRESS tanks cannot be buried or backfilled. This voids the warranty. For underground installation, Promax has a separate underground tank range.

Installing a small tank

The tank is placed on a level, compacted surface. For tanks up to 1,000L, a compacted gravel pad is sufficient. For tanks 2,000L and above, a concrete pad or reinforced gravel base is recommended to distribute the weight evenly.

Position the tank near a downpipe for rainwater collection. The overflow outlet diverts excess water away from the house foundation. The bottom outlet connects to a pump or gravity-fed system.

For slimline models (narrow tanks), a wall or fence provides additional support. Promax slimline tanks are supplied with a built-in seismic bracing system.