Plumbing

GRAF Carat
Underground Rainwater Tank

There is one problem with traditional tanks. The space they take up in a backyard. And the space they take up on the back of a truck. GRAF’s solution to both problems is so obvious you wonder why it hasn't been done before. It's an underground tank that comes in two halves which sit neatly inside each other, making it much easier to transport and install. Your customers can now store rainwater without losing any space in their garden.

  • Capture water from all downpipes.
  • Save valuable space in the garden.
  • Better water quality through superior filtration & underground storage.

What are the benefits of underground tanks?

Saves valuable space.
Assists in keeping water cooler.
Tanks are hidden from view.
Potential algae growth is eliminated.
Protection from vandalism or accidental damage.
Rainwater can be collected from all downpipes rather than one or two as with above ground tanks.


Where can I find information about installation and maintenance requirements?

Please refer to the Installation Instructions.


How much do the tanks weigh? Is a crane required to lower the tank into the ground?

Graf tanks vary in weight from 120kg (2700 litre tank) to 220kg (6500 litre tank). Tanks can be lowered into place using digging machinery and a crane will not be required.


How long does it take to put a tank together?

The two tank halves can be assembled in 15-20 minutes. Click here to view the installation video.


How much rainwater will i collect?

As a rule of thumb: 1mm of rainfall on 1 square metre of roof space = 1 litre of water


What fill material should be used?

Crushed Rock (Type B) is the recommended fill for the surrounding trench. Other suitable fill materials can be found on page 3 of the Installation Instructions.


Can the tank be installed where groundwater is an issue?

Carat Underground Tanks have been specifically designed to ensure that the tank will not float in areas where groundwater is present. Tanks can be installed securely even in areas where groundwater reaches the middle of the tank without the need for ballast or concrete. If groundwater is higher please contact your local Reece branch for further information.


Is ballast or concrete required to hold the tank down?

The Carat Underground Tank was designed to maintain its installed position without the need for additional concrete weight or anchors. Installation integrity is also preserved when the water level is low, with no requirement to maintain a minimum water level to act as ballast. These features ensure that installation costs are reduced and the full capacity of the tank is always available to the user.


How much weight can the lid take?

The standard lid will accept pedestrian traffic up to 150kg. The vehicular lid will accept passenger vehicles up to a gross vehicle mass of 12 ton.


Do I need to fill the tank with water prior to backfilling?

The tank should be filled 1/3 with water before backfilling the surrounding trench.


What is the warranty on the tank?

All Graf tanks come with a 15 Year Manufacturers Warranty, backed by Reece Customer Care.


Getting Started

When deciding on tank size and other options, it’s important to first calculate your total household requirements.

Please enter the following details so we can recommend a tank size for you.

Postcode

   (why we need it)


Purpose

Indoor (e.g. laundry, toilet)
Outdoor (e.g. garden, swimming pool)
Both


Daily Water Usage

Litres    (how to calculate daily water usage)


Roof Area

m²    (how to calculate roof area)


step 1 - select a tank size

The Graf Carat tank is available in four base sizes ranging from 2,700L through to 6,500L. However, the modular system allows multiple tanks to be used in combination, so storage capacity can be increased to suit your needs.

It is also a good idea to look at your water rates notice. It'll give you an indication of your current usage.

Please select the size your Graf Carat Tank

Graf Carat Tank
Graf Extension tank

Optional Extension tank (enter quantity)
The Carat innovative modular system allows multiple tanks to used in combination with the primary tank, so your storage capacity can be increased.

2700 Litres Product code: 9501228 3750 Litres Product code: 9501229 4800 Litres Product code: 9501230 6500 Litres Product code: 9501250

step 2 - select a lid

step 3 - select a filter

The type and quality of your filtration set-up will directly effect the quality and cleanliness of the your water supply. Garden applications require minimal filtration while in home applications demand a much higher standard of filtration.

Please select a filter for your Graf Carat Tank



step 4 - select a lid

The pump you choose will need to deliver suitable pressure for all your applications around the home. If you're only using tank water for your garden, then a smaller capacity pump can be used. If you're using tank water for both garden and household applications, a larger capacity pump will be needed.

Should your installation have different requirements, please contact your nearest Reece branch regarding other pump options. Please select a pump package