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Frequently Asked Questions

1. Why do I need a water tank?    

In some jurisdictions, governments require the construction of new / existing homes to include rainwater tanks to supply water for toilet flushing, laundry and outside use such as topping up your pool or capturing rainwater from sheds / roof areas (refer to your local council requirements). Capturing natures precious chemical-free resource can also help you save money and is environmentally friendly!  


2. What are the main benefits of having a rainwater tank? 

- You can save money on water bills by capturing natures free, renewable resource!

- Rainwater can be used to drink, flush toilets, wash clothes, water the garden, wash cars, top up pools / spas and more! 

- Rainwater is chemical free and is captured from the roof surface. 


3. What size tanks do you make?

We make 19 different sized tanks in slimline, round and underdeck varieties, starting from 1,000 litres, up to 10,000 litres. We also sell LILO underground tanks that are made in Western Australia in 1500, 3,000 and 5,000 litres.  

Our tanks come in a variety of dimensions; standard, super slim, tall and lowline. Check out the links above to see the dimensions. 


4. Do you have tanks in stock / available to buy now? 

Unfortunately we cannot stock every size and colour at once. At times we may have stock available, so if you are in a hurry it is worth giving us a call to check if we have your desired size / colour instock. If not, we would be happy to manufacture one for you based on your requirements. Production time to make a tank is approx 4-5 weeks. 


5. What colours do you have available? 

We offer over 25 colours to choose from in our slimline, round and underdeck tank range. Our colours are equivalent to Colorbond colours. Choose a colour that compliments your brick, gutter or roof colour or blends into the natural environment. 


6. What material are your tanks made from? 

Our tanks are made from Polyethylene. 


7. What does an Enviro Water Tank tank come with? 

All tanks purchased direct from Enviro Water Tanks include:

  • Leaf strainer (fitted to the inlet)
  • Ball valve 25mm
  • Overflow connection (Mozzie Stoppa) 90mm
  • 2 or 3 x 25mm brass outlets moulded into the tank (at ankle / bucket height - this varies based on the model / size of tank) - these come sealed so can be cut out with a holesaw according to your requirements.


​8. Do you deliver? Where do you deliver? 

Yes, we deliver to accessible front of site properties in the Sydney metro area, Central Coast, South Coast in NSW and some areas of the ACT. To confirm we can access your site, we will need to check the exact address. It is helpful for you to advise if the street/site is steep, narrow or is a cul-de-sac etc as our truck and trailor can be up to 20 metres long. Please call us on 1300 73 72 10 for a delivery quote. 

We offer a free tank delivery to Sydney metro suburbs as long as they are accessible for our truck / trailer. If it is not accessible, we can often use a courier however there will be an additional fee. Please call us and we would be happy to check your address! 

Our truck and trailer is approx 19 metres long and requires a large area to turn around.  


9. Can I pick up a tank from you if you don't deliver to my area or if I need it right away? 

Yes, we offer pick up for private orders - it is best to call us prior to ensure the tank is available and to confirm the time and date you wish to pick up. You are responsible for securing the tank to your vehicle, it is best to use load straps to do this. Round tanks are best to travel on their side, and slimline tanks are best to travel standing upright.  


10. How do I install my tank? 

In order to warrant an Enviro Water Tank tank, the following installation and site preparation points must be adhered to; 

1. Ensure that the area chosen is stable original ground and not filling soil.
2. All Enviro Water Tanks tanks must be on a level base of concrete 100mm thick with a minimum strength 25m.p.a. and one layer of F72 reinforcement.
3. Concrete must extend a minimum of 30mm outside of the tank perimeter of the tank.
4. Crusher dust may be used but must be a minimum of 75 mm thick, compacted and the outside edge must extend a minimum of 30mm outside of the tank's perimeter with edges concreted so the tank cannot be undermined.
5. All tanks come complete with a ball valve and fitted leaf strainer and 90mm (Mozzie Stoppa).
7. Polyethylene tanks will expand when filled. Allowance for expansion is required when plumbing work is carried out.
8. Clean leaves and debris from the leaf strainer on a regular basis.

To attach the Mozzie Stoppa to the overflow hood, you will need to cut / drill a 90mm hole using a holesaw. Using the screws (provided) and some silicone. You need to be able to access the Mozzie Stoppa to be able to clean it regularly. 

Alternatively, the Mozzie Stoppa Easy-Clean ($8) has a mosquito-proof 955 micron stainless steel screen that flips open on a simple, spring-loaded hinge for super-Easy-Cleaning and maintenance. Simply unlatch the screen, brush or hose off any dirt and return it to the closed position. Must be purchased separately, not included with tank, subject to availability. 


Standard 90mm Mozzie Stoppa (included with tank) 


Mozzie Stoppa Easy-Clean $8.00 (not included with tank)


The 25mm outlets in the tank come sealed so you will have to drill these out using a 28mm holesaw to then attach the ball valve or pump connection pipe (flexible coupling). 

*We can drill out overflows / outlets for you if you request these at time of order*

25mm brass outlets are moulded to the tank at ankle height and bucket* height (depending on tank size) during production - these come sealed to enable you to choose the best position of where you need to release the water from. They can be drilled out using a hole-saw (be-careful not to leave any plastic inside the tank which can cause blockages).  


25mm ball valve (included with tank purchase) connected to 25mm moulded brass outlet at ankle height. This is where a piece of flexible coupling / hose can be connected to connect to a pump. 

**We recommend using a licensed plumber to install your water tank and pump to ensure the downpipes/inlets/outlets are set up correctly. 


11. Do you sell your tanks in retail stores? 

Yes, Enviro Water Tanks tanks are available to order from leading hardware and plumbing stores including Bunnings, Mitre 10, Eagles Plumbing, Tradelink, Reece, Southern Plumbing and some private tank retailers. These stores are located between Sydney and Coffs Harbour to the north, including the Central Coast, Taree, Forster, Port Macquarie, Kempsey and Coffs Harbour. To the west including Bathurst, and to the south including Albion Park, Wollongong and Batemans Bay. 


12. Do the tank sizes vary?

We do our best to list the measurements to be as accurate as possible, however they may vary slightly due to the manufacturing process. 


13. Can I join two or more tanks together? 

Yes, you can join tanks together using flexible coupling / hose. The flexible coupling connects to the ball valve, located at ankle height (one ball valve provided with each tank purchase) which attaches to the moulded brass outlet on the tank. You can also connect the tanks where the overflow hoods are positioned using PVC pipe (a plumber is probably best to do this). Having two joins means that the tanks will fill up faster. Feel free to call us to discuss this or speak to a plumber. 


14. Where are you located? 

Enviro Water Tanks tanks are manufactured in South Windsor, NSW Australia. We are a family owned Australian business. We have tanks on display if you want to come and have a look at what we offer and have friendly, helpful staff available to answer your questions. We are open Monday to Friday, 7.30am - 5.00pm (closed public holidays). 


15. Do you accept tank / pump returns if I change my mind or the colour/size isn't right? 

Sorry, we don't accept returns for incorrect size / colour ordered. Please check the dimensions of the tank before you order to ensure it fits into the space. Pick up a Colorbond colour swatch from your local hardware store to check what colour tank would suit. Ask us for the specs of the pump or check them out here before you order to check that it meets your requirements. 


16. How long will it take for my tank to fill up with rain water?

Obviously, this is dependent on the volume and timing of rainfall in your area. To calculate the run-off from your roof, 1mm of rain on 1 square metre of roof will deliver 1 litre of water into your tank. As a rough guide:
• An average 1 car carport is 25 square metres
• An average 3 bedroom house has a roof surface area of approx. 150 square metres
• An average 4 bedroom house has a roof surface area of approx. 200 square metres. 
• An average 5 bedroom house has a roof surface area of approx. 300 square metres

So, if you have an average 3 bedroom house and a 3000L tank, it would take 20mm of rain to fill your tank.


17. How much water do we use?

On average each of us uses 147 litres of water per day. This equals around 53,000 litres per year!

Average water use as a percentage breakdown; 

• 30% shower    • 20% outdoors    • 19% tap bath and other    • 16% washing machine    • 14% toilet    • 1% dishwasher

18. What benefit is there to using rainwater to connect to the toilet / laundry?

By using natures chemical-free renewable resource, you can save on water bills and be kinder to the environment. Did you know that a toilet single flush uses approx 5 litres of water per flush, a front loader washing machine uses approx 60 litres per load and washing your car for 10 minutes can use up to 200 litres? Many new houses require installation of a rainwater tank with a pump that services toilets and laundry to aid in stormwater management and to make the most of the free, clear, resource we call water!


19. Is the tank water safe for drinking?

With emphasis today on the environment, sustainability and climate change, we are proud to announce that the products we use are heavy metal-free.  

Enviro Water Tanks use environmentally friendly products. We do not add Phthalates (typically di-2-ethylhexylphthalate (DEHP) also sometimes known as Dioctyl phthalate (DOP), benzyl butyl phthalate (BBP), and Dibutyl phthalate (DBP)) nor Bisphenol A. 

Powder used in the manufacture of our tanks contains absolutely no toxic heavy metals such as lead, cadmium and chromium. This complies with the Australian and New Zealand Standards. 

We guarantee you an environmentally friendly quality product which is 100% food safe for the whole family. 

To keep your tank water extra clean, ensure you maintain and clean your roof / gutters regularly. In addition, we recommend installing a first flush and leaf eater


20. Where can I have the overflows and outlets on my round tank? 

The below diagram shows 4 options as to where the overflow can be drilled out (3 / 6 / 9 / 12 o'clock).

The 25mm brass outlets are positioned at 3 and 9 o'clock. 

We can drill these out for you (let us know at time of order) or you can do it using a holesaw. 


21. Why should I purchase an Enviro Water Tank tank?

We are a small local business in the Hawkesbury that prides ourselves in providing friendly and efficient customer service. In addition; 
• Enviro Water Tanks tanks comply with AS/NZS 4766:2006
• We go beyond meeting the Australian standards in water tank manufacturing
• Our tanks are designed by a structural engineer so you have peace of mind knowing you are investing in a good quality product
• Our tanks come with a 20 year warranty when installed according to our guidelines
• All tanks have been tested using a simulated engineering analysis to show that all Enviro Water Tanks can withstand huge pressure beyond what   is accepted in the industry
• Tanks are made in one piece construction without seams, eliminating the risk of tears or splits
• Brass fitting inserts are moulded into the tank for a complete leak-proof seal


22. Do I need to disinfect my water tank?

Regular disinfection should not be necessary. However, if you suspect that water in the tank is contaminated, it can be chlorinated by adding powdered swimming pool chlorine (calcium hypochlorite, 65 per cent available chlorine) or liquid chlorine (sodium hypochlorite, 12.5 per cent available chlorine). You should not use stabilised chlorine (chlorine cyanurates).

 It takes about 5 milligrams of chlorine per litre to disinfect your tank. This is equivalent to 7 grams of calcium hypochlorite or 40 millilitres of sodium hypochlorite per 1000 litres of water. A level dessert spoon may be used as an approximate measure for 7 grams of powdered calcium hypochlorite. A lot of the chlorine may be used up during disinfection. There should be at least 0.5 milligrams per litre free chlorine, 30 minutes after the chlorine is added – you can use a pool chlorine test kit to measure how much chlorine is in the water. Note that milligrams per litre is the same as parts per million.

You should be able to smell the chlorine faintly an hour or so after treating the water. If you can’t, you may need to add a similar amount of chlorine again. Ideally the tank shouldn’t be used for at least 24 hours to allow the chlorine taste and smell to dissipate and for harmful microorganisms to be destroyed.

It is important to follow the manufacturer’s instructions. Filters should be correctly installed; maintained and replaced regularly otherwise they will become ineffective and can allow bacteria to grow that are then released into the filtered water. Please contact your local Public Health Unit for further advice on disinfection and filtration.