How to Keep Water in Your Rainwater Tank Safe and Clean

A rainwater tank can be a good choice for collecting water you might use for watering the garden or lawn, or even for watering chickens and other livestock. You can also use rainwater for everyday chores like washing the car or your dogs. Even if you don't plan on using that stored water for drinking, you still want to keep it clean and free of algae, bacteria and other such contaminants that could harm your garden or irritate your pet or leave marks and build-up on your car. Note a few tips for how to keep the water in your rainwater tank safe and clean for any use.

Cleaning the roof and gutters

Most rainwater tanks are placed in an area of the property that will allow them to catch water from the home's roof and downspouts. If the roof and gutters of the home are covered in debris or filled with sludge, the water will then bring those contaminants with it as it fills the tank.

Power washing your home's roof as often as needed to keep it clean and also cleaning out the gutters regularly will reduce some of that sludge and debris that would otherwise make its way into the rainwater tank. It's also good to put a screen over your home's gutters to block even more debris.

Tank screen

Mosquitoes are drawn to standing water, and these insects can leave behind larva and other contaminants in your rainwater tank. A mosquito screen over the water's surface can keep these bugs and other pests from landing on the water for a drink and polluting it in the process. You may also need to clean the screen regularly to remove any contaminants that might make their way into the water from the screen.


Even with the best of screens and regular cleaning of the gutters, your rainwater tank will usually still develop sludge and debris at the bottom. Unless you have a very small tank that you can easily empty and then hose out yourself, it's good to have your tank cleaned by a professional on a regular basis; a professional rain water tank cleaning company can pump out any standing water and thick sludge that has collected at the bottom of the tank, then clean it thoroughly and add a sanitizer. This will ensure the entire tank is clean and free of contaminants, and it will also keep new water you collect cleaner for much longer.