Rainwater Treatment Maintenance Guide
Using a rainwater supply? Read our maintenance guide to keep your tank clean and ensure safe, high-quality water flows into your home.
Rainwater Treatment Maintenance Guide
Rainwater collection is a great practice and is becoming increasingly popular. However, it is essential that water is collected and stored correctly, then maintained regularly, so it is fit for consumption. The following sections of this guide provide advice on how to ensure your water is clean and safe to use. Click here to see recommended rainwater filter products for keeping your rainwater safe and treated.
1. Evaluate Your Rainwater Collection Environment
The catchment area directly affects the quality of rainwater collected, so it is important to evaluate your needs, whether upgrading an existing system or planning a new build. Once you have assessed the catchment area, you will have a clearer understanding of the products required to design an effective system. This section will help guide those selections.
Rainwater itself is generally very clean, however during the collection process it can become contaminated by airborne particles or materials from roofs, gutters and the water tank itself. As a result, the quality of rainwater is strongly influenced by the surrounding environment, local activities, climate and the rainwater collection system used.
Rainwater is also typically slightly acidic, meaning substances it comes into contact with can be carried through the system. Once the water enters the tank, there are further opportunities for contamination that should be minimised. It is therefore important to take steps to protect water quality from initial collection and storage through to consumption.
Tank Types
The material your tank is made from can greatly affect water quality while it is stored.
- Plastic tanks - The most common option. Plastic does not rust, however some tanks may impart taste or odour, which can be addressed with a taste and odour filter.
- Galvanised steel tanks - These are susceptible to rust, which can result in rust flakes entering the water. This can be addressed with a sediment reduction filter.
- Concrete tanks - Concrete contains limestone, which can help neutralise the acidic nature of rainwater. In some cases, this may contribute to white spotting due to water hardness.
Existing Tank Installations
If you already have tanks installed at your property, it is important to carry out a thorough system check to ensure everything is functioning correctly.
- Check gutters and downpipes feeding the tank to ensure they are clean and in good condition.
- Ensure appropriate screens are installed to prevent leaf litter and debris entering the tank. Leaves and debris can cause discolouration, odour and support the growth of microorganisms.
- Ensure direct sunlight cannot enter the tank. Light encourages bacterial and algal growth, so openings and inlets should be properly sealed and screened.
- Inspect the tank for structural integrity, including signs of rust, cracking or deterioration.
The Surrounding Environment
The surrounding environment where the tank is located will affect rainwater quality.
- Chemical overspray from crop dusting or spraying activities, which can be reduced using a carbon-based filtration system.
- Dust from nearby farming or industrial activities.
- Wildlife, vermin, bats and insects – fine mesh screens should be installed on tank inlets and guttering.
- Ash and soot from burn-offs can impact water quality. A first flush diverter helps reduce the amount entering the tank, and carbon filtration can assist if contaminants enter the water.
- Tannins from tree leaves and branches.
If contamination is a significant concern in your area, we recommend contacting our water treatment team to discuss suitable options.
Your Roof
- Roofs are constructed from a range of materials and may contain asbestos, lead flashing, paint or solder. These materials can contaminate rainwater as they corrode, crack, flake, deteriorate from UV exposure or leach substances, which can compromise water quality.
- Roof-mounted appliances such as air conditioners or hot water systems should not discharge onto roof catchment areas or gutters.
- Prevent leaves, vegetation and pests from entering the tank by installing gutter mesh.
- Check for lead flashing, particularly around heaters or roof penetrations, as this may introduce lead into the water supply.
2. Designing a Household Rainwater System
Selecting the right rainwater system helps protect household water quality and provides peace of mind. Consider which areas of the property will use rainwater and determine an appropriate budget before selecting equipment.
- A. Maximise your catchment area by using the cleanest sections of roof, positioned away from trees and vegetation.
- B. Install gutter mesh to prevent leaves, vegetation and pests entering the system. A first flush diverter helps isolate the most contaminated water from the initial rainfall. Ensure tanks are sealed, screened and protected from sunlight.
- C. Select a suitable pressure pump to ensure adequate pressure at outlets. A minimum pressure of 300 kPa is recommended.
- D. (Optional) Rainwater is often acidic and can react with copper pipes, causing blue-green staining. Installing a pH correction system such as the Puretec NTS Series can assist in addressing acidity.
- E. Identify areas of supply, such as kitchen, bathroom, laundry, garden or garage. If supplying toilets only, a stand-alone filter may be sufficient. For showering and drinking, a system designed to protect against bacteria is recommended.
- F. Select a suitable filtration system. The Hybrid series incorporates Radfire™ UV technology designed to significantly reduce bacteria. Hybrid G systems include a weather cover for outdoor installation, while Hybrid R systems are designed for indoor use.
3. Monitoring and Maintenance
Ongoing monitoring and maintenance are essential to support safe water use throughout the home, particularly for drinking water. While preventative measures begin at design and installation, regular upkeep is critical to maintaining water quality.
- A. Trimming trees and vegetation
Keep the roof catchment area clear of overhanging branches to reduce leaf build-up and discourage birds and animals. - B. Prevent debris entering the tank
Use leaf and debris diverters on tank inlets. Install a 1 mm mesh on inlet strainers and overflows to deter mosquitoes, insects and vermin. Prevent downpipe blockages to reduce backflow and flooding risks. - C. Keeping gutters clean
Keep gutters clear of debris, moss and lichen. Gutter mesh can help reduce maintenance and minimise contamination risks. Inspect roofing and gutters every six months. - D. Keep vermin and pests away
Install appropriate barriers such as mesh to prevent animals entering tanks. Remove roof roosting areas to limit contamination from birds. - E. Clean tanks regularly
Inspect tanks for sludge accumulation at least every two years. Sludge can be siphoned or removed during tank cleaning. Excessive sludge can harbour bacteria. - F. Regular flushing with TankSafe™
Periodic flushing helps reduce sediment, algae and unwanted build-up within the system. Systems with UV should be dosed annually. Systems without UV should be dosed every two months. - G. Filter system maintenance
Filters and UV lamps must be replaced at recommended intervals to maintain performance. Blocked or exhausted filter media can restrict flow and reduce effectiveness. UV lamps should be replaced every 12 months.
For further information, contact the Customer Care Team for assistance.
If you have further questions about rainwater filtration or would like to learn more about the rainwater filtration product range, please contact us.
Find the Nearest Dealer
Puretec is the preferred water filtration supplier among the plumbing, building and irrigation stores. To find out more about product stock, we recommend calling your chosen store prior to visiting.