Note: If you wish to connect your tank to internal plumbing (such as a toilet and washing machine), connections must be completed by a licensed plumber in accordance to the Plumbing Code AS/NZS3500.

QTank have put together instructions for positioning tanks, connecting downpipe/s, overflow management and install, connecting valves to tank outlets and more. What follows has been extracted from QTank's more complete Easy Install Guide (PDF).

1. Positioning Your QTank

If you know where you want to locate your tank, and your base is ready, the QTank driver who delivers your tank will assist you to position it in place. If not, all you need to do is:

  • Locate your tank’s overflow – a hole cut in a vertical part of the tank’s roof with a strainer fixed to it. Position the tank so the overflow is in the easiest location for how you plan to use it.
  • Locate the outlets on your tank – position the tank so the outlets are easy to reach. When your QTank is positioned where you want it, add approximately 2.5cm (1”) of water to it to secure it in place.

2. Connecting Downpipe/s to Your QTank

What you’ll need to buy:

  • PVC piping (90mm diameter)
  • PVC elbows
  • PVC connector/s
  • PVC glue/cement
  • PVC pipe holders (with anchor brackets)
  • metal screws (self-tapping)
  • sandpaper

Tools you’ll use:

  • tape measure
  • spirit level
  • ladder
  • hacksaw
  • drill
  • screwdriver

If you are installing a Leaf Eater Downpipe Rain Head or First Flush Diverter, installation instructions will be enclosed with the products.

  • You’ll be able to purchase all you need for the job from hardware or plumbing stores.
  • Buy a little more PVC pipe that you need in case you make any errors during the installation.
  • Having someone help you with the installation will make the job easier, faster and safer.
  • For a cleaner look, position the parts of the PVC with printing on them towards the wall so they’re less visible.

1. Draw a plan of how you will connect the downpipe/s to the tank – calculate how much pipe, and how many elbows and connectors you’ll need to buy.

2. Once you’ve got your supplies, remove the downpipe by cutting it to uncover the metal flange inside.

3. Before starting to glue the PVC parts together, measure, cut and click them together without glue to ensure you have all the parts you need. Then, you may find it useful to lay them out in position on the ground ready for easy gluing. Identify sections to connect together – for example, the top third of the plumbing might be a natural place to connect and install before connecting and installing the second third.

4. Use sandpaper to smooth the edges of the pipes after cutting them.

5. Select the pieces for one section, add glue to the joins and connect them quickly.

6. Drill holes in the PVC connector to accommodate the self-tapping screws.

7. Screw the holding bracket mounts to the wall near the flange on a very slight downwards angle, which allows the water to flow towards the tank. (Use your spirit level to check the angle.)

8. Attach this section. Continue then to connect and attach the remaining sections.


  • Please be aware that because these tanks are made of Polyethylene they can expand and contract. When filled with water the sidewalls may expand this is normal and will not effect the structural integrity. Please allow for this when installing the pipework and the placement beside a structure.
  • QTank's 5000L Slimline Standard tank should not be used within one kilometre of the ocean unless the metal supports have been replaced with Stainless Steel supports. Please contact Tank Shop for a quote.
  • When installing the overflow please ensure that the internal bend is facing upwards. Please see QTank’s install guide on YouTube:

3. Managing Overflow From Your QTank

When your tank is full, water is directed through the overflow to release the extra water and pressure from the tank.

Fitting your overflow

There are a number of overflow positions on each QTank. If you are unsure where your overflow should be fitted please contact one of our friendly customer service team

1. After selecting the appropriate position on your tank, you will need to drill a 95mm hole to accept the overflow kit provided.

2. To fit the kit into your tank, insert the elbow section of the kit into the 95mm hole.

3. Rotate the kit slightly so the mouth of the elbow is facing upwards at approximately 45 degrees.

4. Push the kit all the way in until the rubber washer is snug against the outside of the tank surface.

5. Attach with the screws provided.

Managing your overflow

There are a few options for managing the overflow from your tank:

  • Fall from the overflow outlet onto the ground near the tank. You could place a few rocks where the water lands to reduce the strength of its flow. With this approach, you should ensure that the pressure and volume of water from the overflow will not affect the stability of your tank’s base. Attaching a piece of pipe or flexible hose to the overflow outlet, to direct the water away from the tanks base is recommended. Check with your local council if this overflow system is suitable.
  • Direct it back into your stormwater system. This could be by connecting the overflow back to the downpipe you have connected your tank to, or connecting the overflow directly into the underground stormwater pipes on your property. You can locate the stormwater pipes by starting at the bottom of a downpipe and digging carefully from there.
  • Direct it into another water tank or pool through piping.

Piping your overflow to stormwater, another tank or pool

  • Plan for and prepare your piping using the same guidelines in 2. Connecting Downpipe/s to Your QTank.
  • Make a snug fitting of the piping to the overflow by using 90mm PVC pipe sections – no gluing is necessary.
  • Provide support to the piping, such as running it down the wall of your tank instead of extending it out horizontally from your tank then downwards. This helps to reduce strain on the fittings and the tank.
  • If your piping will run a long distance from the tank, consider using a piece of flexible pipe at the connection which will absorb movement in the piping.
  • Connect two or more tanks at the base by a flexible hose or pipe, and at the top via the overflow so they will increase and decrease in level equally.

4. Connecting Attachments to Your QTank

Your QTank will be supplied with two threaded outlets already moulded into the tank. The threads do not protrude out from the tank so it is easily rolled into place.

A ball valve and tap fitting come supplied with your tank. You will be able to install the ball valve and tap fitting easily by matching their threads with the thread in the outlets. To ensure a good seal, apply some thread tape to the fittings before carefully screwing them into the outlets using a shifter or a spanner.

If you want to make additional outlets in your tank, call QTank on (07) 3881 0208 to discuss the products required to do this.

Installing a pump

If you buy a pump to connect to your QTank, installation instructions will be enclosed with the pump.

5. Testing your QTank

With just a few steps, you can inspect your tank and test that it is ready for use:

  • Check that all of the tank’s fittings, such as the leaf strainer, are correctly inserted and secured.
  • When your tank fills with rain water, check the connections for any drips.

6. Maintaining your QTank

Tanks require little maintenance. Taking these steps regularly will ensure top performance from your tank:

  • Check and clean your gutters, roof and tank screen.
  • Remove nearby tree branches which may drop leaves into the water catchment area.
  • Check and clean if necessary the overflow screen mesh from any build up or obstruction.
  • Check your tank for sludge every two to three years which may collect at the base, and have it cleaned if necessary.
Disclaimer: Information on this page is provided as a general guide to help with installing rainwater tanks. Tank Shop and its partners are not liable for any actions you take in relation to the information or instructions on this page. You assume full responsiblity should you choose to proceed with any advice.