3,000LENDURO7 colours
Corrugated strength in a compact tank. Bury it to a third of its height.
$1,466.00
Shop this tankSmall water tanks
Discover Promax Small Water Tanks
From 120 litre garden tanks to 5,760 litres of home rain storage - New Zealand-made, drinking-water safe, delivered to your gate. Order online and pay by card.
Order online, pay by card
Slimline options for tight spaces
Our strongest, most versatile tank.
- Sizes from 450L
- Corrugated sidewall
- Bury up to a third of its height
- 7 colour options
- Drinking-water safe
Made in New Zealand since 1985
AS/NZS 4766 certified
5-year warranty on small tanks
Delivered nationwide
Top picks
Our most popular small tanks.
The small tanks New Zealand homes and gardens order most. Online pricing - the price you see is the price you pay.
5,000LENDURO7 colours
Serious home rain storage without the big-tank footprint.
$2,060.00
Shop this tank
Lead times are shown on each product page and at checkout.
Choose your range
ENDURO, XPRESS or Slimline?
All three are genuine Promax tanks built to the same standards. ENDURO is the strongest and most versatile, XPRESS is the sharpest price per litre, and Slimline fits where round tanks cannot.
ENDURO
Our strongest, most versatile tank. The corrugated sidewall is the Promax signature - and the reason it can do things other tanks cannot.
Colours
7 colours
- Corrugated sidewall for extraordinary strength
- Bury it up to a third of its height
- Sizes from 450L to 5,000L, including Low Profile
- 7 colours to match your place
From$545.00
Shop ENDURO
XPRESS
Genuine Promax quality at a budget-friendly price. Not a cheap imitation - a real Promax tank with the extras trimmed to hit a price.
Colours
2 colours
- Same premium UV-stabilised plastic, blended in-house
- Same heavy ribbed roof construction
- Same warranty for its size as the ENDURO
- Sizes from 2,500L to 5,760L
From$1,036.00
Shop XPRESS
Slimline
Flat-backed tanks that sit tight against a wall or fence - serious storage where space is the constraint.
- Flat back hugs walls and fences
- Sizes from 1,000L to 5,000L
- Tank-and-pump combos available
- Ideal for tight urban sections
From$2,297.00
Shop Slimline
All built without compromise:
Heavy ribbed roofOne-piece, seamless constructionPremium UV-stabilised plastic, blended in-houseAS/NZS 4766 certified, drinking-water safeNZ family-made for 30+ yearsDelivered nationwide
Browse the range
Find the small tank that fits your place.
ENDURO is our strongest small tank and the safe pick for most homes and gardens. XPRESS keeps the same Promax quality at the sharpest price. Slimline tucks in against a wall where space is tight. Pick a range to compare every size.
Select your range
450 - 5,000 L
ENDURO water tanks
Corrugated walls for extraordinary strength, up to seven colours, and sizes from garden top-up to serious home storage.
Best forHomes, gardens and sheds
ColoursUp to 7 options
Volumes450 - 5,000 L
Select your size
2,500 - 5,760 L
XPRESS water tanks
Smooth-wall construction and the sharpest litres per dollar in the range. Mist Green or Dark Grey.
Best forMaximum litres per dollar
Colours2 options
Volumes2,500 - 5,760 L
Select your size
1,000 - 5,000 L
Slimline water tanks
Flat-backed tanks that sit tight against a wall or fence - serious storage where space is the constraint. Tank-and-pump combos available.
Best forTight urban sections
FootprintFlat-backed, wall-hugging
Volumes1,000 - 5,000 L
Select your size
Tank only
Tank and pump
Tank-and-pump combos are listed alongside the tank-only options.
Rain harvesting
Rain harvesting accessories
Leaf diverters, filters and fittings that keep the water in your tank clean. Add them to your tank order and everything arrives together.
Best forCleaner stored water
Works withEvery Promax water tank
RangeDiverters, filters, fittings
After serious volume?
Tanks from 10,000 to 30,000 litres have their own page - including every tank in the Big Tank Sale.
Proof
Tanks that have already gone to work.
Real installs from our case studies - small tanks doing serious work on real New Zealand sites.
20,000+
tanks delivered since 1985
2
factories - North and South Island
7
ENDURO colours to match your place
Their 3,000L ENDURO has never frozen - even at minus 9 degrees - and an autumn fill from a 30 square metre roof carried their tiny home right through a Queenstown winter.
Six 5,000L Low Profile tanks, linked together on a steep Northland site, harvest rain for a family home where a single big tank simply would not fit.
28 ENDURO tanks supplying the township were shaken by the magnitude 7.8 earthquake at forces of around 3g - no failures. Locals now call them 'the tanks that withstood the earthquakes'.
FAQ
Before you order.
What size small water tank do I need?
Garden watering and stock top-up: 450L to 2,000L is usually plenty. Washing down, troughs and small-scale irrigation: 3,000L to 5,000L. If you are harvesting rain for household use, remember a small tank fills quickly - every 1mm of rain on 1 square metre of roof collects 1 litre of water - so it may be worth looking at a larger tank. Not sure? Send us your details below and we will recommend a size within one business day.
ENDURO, XPRESS or Slimline - which should I choose?
ENDURO is our strongest small tank: corrugated walls, up to seven colours, sizes from 450L to 5,000L, and the only range that can be partially buried. XPRESS delivers the same Promax quality with smooth walls at the sharpest price, from 2,500L to 5,760L. Slimline tanks are flat-backed for tight spaces - 1,000L to 5,000L, with optional pump packages. If you are unsure, the ENDURO is the safe pick.
Are poly water tanks safe for drinking water?
Yes. Promax tanks are made from premium UV-stabilised polyethylene that we blend in-house, compliant with AS/NZS 4766 and suitable for storing potable water. Poly will not rust, crack or leach like some older tank materials, and the sealed one-piece construction keeps light and contaminants out of your stored water.
How long does a poly water tank last?
Decades. Our UV-stabilised polyethylene is engineered for New Zealand's harsh sun, and the one-piece construction means there are no joins or seams to fail. Small tanks carry a 5-year warranty and are made from the same materials as our large tanks, which carry 20 years.
Can I bury or partially bury my water tank?
Only the ENDURO. Small ENDURO tanks can be buried up to a third of their height - useful for downpipe fall, sloping sites, or keeping the tank low along a fence line. XPRESS and Slimline tanks are above-ground only.
What site preparation does my tank need?
Poly tanks need a flat, level, well-compacted base that fully supports the tank floor and is slightly larger than the tank's footprint - compacted basecourse topped with sand or crusher dust is the common approach. Keep the pad clear of roots, rocks and sharp objects. Full site preparation guidelines are on each product page, and our team can talk you through your specific site.
How does delivery work and when will my tank arrive?
Tanks are made to order at our North Island and South Island factories and delivered nationwide. Lead times are shown on each product page and again at checkout, so you know the timing before you pay. Delivery is arranged after you order and depends on your location - the team confirms the details with you directly.
Still got questions? Ask the team →
Ask an expert — it's free.
Talk to our team.
Our team knows this range inside out. Tell us about your build, what you're trying to achieve, where it's going, or what you're unsure about and we'll come back with a clear recommendation. No jargon, no obligation.
- Personalised product recommendations for your specific project
- Spec, compliance and sizing guidance included
- Fast replies — usually within one business day
Trusted by NZ homeowners, builders and specifiers since 1985.