STC Blog

Why Clean Your Rain Water Tank


Rainwater is a free resource easily captured using simple equipment and is widely used throughout Australia for domestic and commercial reuse. This sustainable alternative to town water for not so critical uses such as toilet flushing and irrigation is a great initiative to save money and reduce the load on the ecosystem. Most rainwater is harvested via rooftops and other hard surfaces exposed to rain and fed into storage tanks unfortunately these surfaces are prone to the build up of dust, debris and leaves so when rainfall occurs make their way down into the catchment pipework. Most harvesting systems have a device called a first flush fitted to capture the worst of this but due to these not being maintained or a sudden deluge of rain these can be overwhelmed and dirt and sediment can make its way into rain water storage tanks.

Dirty Tanks and Pathogens

Pathogens and bacteria are microscopic organisms that can cause disease, the very things you don't want in your rainwater tanks. These pathogens are everywhere but three things are needed for the water borne version to thrive oxygen, water and food remove one or two of these and those pesky little bugs die off. Unfortunately for water tanks they possessed two of these pretty much all the time but one source we can control the food. Sludge at the base of water tanks can be just that food source you don't want to dish up to these little fellas the best preventative is clean tanks

Distribution Pumps and Pipes

Rainwater harvesting systems most commonly have an electric pressure pump and a changeover switch to distribute the collected rainwater to the location of use. Most of these pumps consist of horizontal or vertical multistage pressure pumps and these pumps do not tolerate much in the way of debris and dirt. Therefore it is very important for the Longevity of this equipment to have dirt in your tank kept to a minimum to prevent damag

Tannins and staining

Another side effect of allowing leaves and back in the Sludge in your tank is the build up of Tannic Acid most if not all native leaves and bark will consist of some level of Tannic Acid as they break down in your sludge. This leads to the staining of any surfaces that are in contact with the rain water the best defence against this problem is a keep your tanks clean and sludge free.

The Solution

The solution to the above points is to regularly maintain your rainwater tanks in a typical maintenance plan would look something like this.

  • Every 3 Months - Service
  • Clean Inlet Baskets
  • Drain and Flush First Flush Device
  • Force the Pump to Run to Check Operation
  • Every 12 Months - Service
  • Replace any System Filters
  • Clean and Check the Inlet Baskets
  • Drain and Clean the First Flush Device
  • Check the Pump Operation and check for sludge build up
  • Clean House Roof and Gutters
  • Every 24 Months - Service
  • Drain Storage Tank
  • Remove Sludge Build up
  • Pressure Wash Internal Surfaces
  • Replace any System Filters
  • Flush and Clean First Flush Device
  • Remove Pump and Check Operation clean with Pressure Washer
  • Check Operation of Mains Changeover Switch

Call us now on 1300 161 380 or fire us an email at