Installation guidelines for Rainwater Tanks

STEP 1: Using the Rainfall and Roof Area Catchment Calculator decide which size round rainwater tank will be best suited for its intended point of use. What you use the rain water for will also determine which pump package you will need. If you are going to be using the water from the tank to flush toilets and run the washing machine a Davey Rain Bank Switch or similar pump package is recommended. This will automatically switch to mains water when the level in the rainwater tanks is too low.

STEP 2: Next choose a suitable location for your round rainwater tank. You should take into consideration that it will need to be located adjacent to a downpipe from the roof gutter so this can be connected into the tank and the tank filled when it rains. (Please check with your local council guidelines).

STEP 3: Your round rainwater tank should be positioned on level ground of stable nature. There are two options for the base material of your round rainwater tank.

Concrete Slab – 100mm thick concrete slab, reinforced with F62 mesh with trowel finish.

Crusher Dust – A crusher dust base should be 300mm wider in diameter than the base of the tank. Remove at least 100mm of natural soil, ensuring the excavation is flat and level. Fill with 75mm of crusher dust thoroughly mixed with dry cement powder to a ratio of 3 bags for 4 meters of base width. Spread out evenly and compact using a mechanical plate compactor. Do not try to compact manually. Screed the top to make sure the finished surface is perfectly level. Do not wet the cement or base as the natural moisture from the ground will do this over time.

STEP 4: Position your round tank on its base ready to be connected to the downpipe and the pump.

STEP 5: Disconnect and remove the downpipe from the gutter that you have decided will feed your rainwater tank.

STEP 6: Using 90mm PVC pipe, bends and a downpipe adapter run your new PVC downpipe from the inlet of your rainwater tank and connect onto the existing downpipe gutter nozzle using PVC solvent cement on all joints. We also recommend incorporating a First Flush Diverter to remove any solids washed from your gutter that could potentially contaminate your tank water. (You will need to measure the gutter nozzle to determine what size downpipe adaptor to use).

STEP 7: Again using 90mm PVC pipe and bends, run from the rainwater tank overflow point down into the stormwater system where the old downpipe used to be connected. This may need to be altered to accommodate the 90mm round PVC pipe.

STEP 8: At the base of the rainwater tank screw in the correct size brass ball valve using Teflon plumbers tape to seal the thread. Depending on the manufacturer and size of your tank there may be two or more outlets at the base of the tank to choose from. Check if you need more than one outlet and more ball valves.

STEP 9: Connect your pump up to the ball valve on the tank using the correct size pipe and fittings. Install a rainwater gauge so the level of the water in your tank can be seen at a glance.

STEP 10: You are now ready to run from your pump to the point of use with poly pipe and fittings. A Sediment Filter should be used immediately after the pump to remove unwanted solids from the water which may cause the toilet inlet valves and washing machine solenoid to fail. (Connection to toilets and washing machine must be done by a licensed plumber).

STEP 11: Plug your pump into the power point and turn the power on. Cover your new pump using a Poly Pump cover to protect it from the elements and reduce pump noise. Your Slimline Rainwater tank is now fully operational and you are ready to start collecting and using rainwater. (A weather proof power point will need to be installed next to the pump by a licensed electrician).

Disclaimer: To insure the above mentioned work is done to local and Australian standards and all work is warranted, we recommend using a licensed plumber and electrician to install all aspects of your Slimline rainwater tank. Using a licensed plumber will enable you to receive the maximum rebates available.