The information provided here is based on our many years of experience in the industry and the information is provided as a guide only and should be used as such.   Always consult your local council and water authority to obtain exact requirements for your particular location.  Please note that requirements for one council may not be the same for another council - check first, it only costs a phone call.

These questions and answers have been compiled by Irrigation Warehouse Group Pty Ltd over a period of years and we try and keep them as up to date as possible.  

What size tank do I need?   The most popular question and if you read the Sydney Water website, they say the minimum should be around 5,000 litres.   My advice is always buy the largest tank that you can fit in the available space.   Now that's great if you have the space and want to water the garden, wash the dog, wash the car and, top up the pool but, what size do you buy if you only have a small garden and only want to water 15 or so pot plants?   1,000 litres is about the smallest volume that is practical.  

Should I buy a round tank or a slimline?   Round tanks are far more economical (lower cost per litre) but, they generally take up more room.   If you have the space, buy a round tank.   If space is a limiting factor, look at the slimline range as they are generally taller but will also normally fit down the unused side of the house.

Can I put a tank under the house?   Yes, provided you have the space.   We have an excellent range of under-house tanks available that are rectangular and they can be supplied in any configuration up to 10 tanks.  

How much rain will it take to fill the tank?   This is a simple calculation.   1mm of rain on every square meter of surface area results in 1 litre of water into the tank.   Let's say that your house roof is 12 meters long by 10 meters wide - 12 x 10 = 120 square meters.   If you had a very brief storm that dropped 1mm of rain on the roof, you would receive 1mm x 120 sq m = 120 litres of rainfall into the tank.   A larger storm comes through and drops 25mm of rain, 25mm (of rain) x 120 (square meters of roof area) = 3,000 litres of rainwater into your tank.   This calculation works for any roof area, all you need to know is the length x the width = square meters.  

Can I drink the water from my tank?   The answer is yes.   Most people who live on farms in Australia drink rainwater that has been caught and stored in tanks.   I would however strongly recommend that before drinking the rainwater, you install a very good quality filter system.  

What goes into the rainwater tank?   The water has fallen onto the house roof and so has a lot of other stuff that you probably don't want to think about but please, let's do.   Stuff that falls from birds, stuff that just floats around in the air and has to land somewhere such as rubber from car tyres, smoggy stuff and all of that other dirt flying around.   In addition you will always have leaves, twigs and other bits and pieces.   All of this is going to end up mixing with your rainwater so we need to keep everything that we can out of the tank.   "Leaf Eaters" will stop leaves and larger stuff and, first flush diverters will take out the first 20 litres of water which would contain most of that "stuff" we don't want to think about.  

To view the pdf file showing the recommended installation drawing - click here.

Two Tank Connection Kit pdf - click here.

Three Tank Connection Kit pdf - click here.

Four Tank Connection Kit pdf - click here.

Under-Deck tank configurations - click here.

To view installation instructions and installation options - click here.

To download the installation sketch for a Grundfos KP pump in a sump pumping to a tank - click here.