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How To Properly Maintain Your Rainwater Tank

How To Properly Maintain Your Rainwater Tank

Rainwater tanks are a great purchase, not only do they help you reduce your monthly water bill, but they also help you reduce your impact on the local environment. However, if you have ever owned a rainwater tank, then you know that they need regular maintenance to continue functioning properly. An improperly maintained water tank is susceptible to dangerous diseases (usually coming from mosquitoes breeding in the tank, or animal corpses beginning to decay into the rain water). So, here are some general rainwater tank maintenance tips; one thing to note is that you will have to get your rainwater tank serviced regularly by a trained professional, a lot of these tips will be more along the lines of “if you see this, call a professional” as opposed to DIY maintenance tips. Doing DIY work on a rainwater tank can be dangerous, especially if your family uses the rainwater for drinking water; so be safe and call a professional if you notice any major problems with your rainwater tank.

Maintenance to the tank itself and the area around the tank

First thing’s first, you should ensure that your rainwater tank and the area around the rainwater tank are properly maintained.

Pipes and taps

Make sure that all taps and pipes on your rainwater tank are above the tank floor, there is no set distance, but generally speaking, pipes and taps should be five centimetres (or more) above the tank. It also depends on the amount of debris you notice; if you notice a lot of debris, then the pipes and taps should be higher if possible.

Covering all entrances

Have you noticed an increased mosquito population around your house since you installed your rainwater tank? If so, then I have some bad news, it is very likely that mosquitoes have begun breeding in your rainwater tanks. Mosquitoes love still water, so rainwater tanks are a natural breeding ground. Once you have your tank cleaned out, the thing you need to do is make sure all entrances into the tank are covered by nylon or mesh. Not only do nylon and mesh covering prevent mosquitoes from getting into your rainwater tank, but the covers also prevent wild animals from getting into your rainwater tank, getting stuck, and then polluting the water in the tank. Mosquitoes and wild animals are vectors for harmful diseases, so make sure you do this ASAP.

Clean your roof

Since the rainwater initially touches your roof, you will want to make sure your roof is clean. But, not only do you want to make sure that your roof is clean, you also want to make sure that you clean your roof with a cleaning solution that is completely non-toxic. Also, while you are cleaning your roof, take the time to clear away any branches that might hanging over your tank (I only mention this because you will likely have to use a ladder to reach your roof, and so you might as well kill two birds with one stone).

Purifying rain water

Even with the best filters in place, if you plan to use rainwater for anything involving humans (drinking water, bathing, etc.) instead of the usual activities of washing clothes, watering the lawn, it is wise to have some sort of purification process in place for the rainwater. There are a few different methods to choose from.


Chlorine is used in rainwater tanks when there is a suspected contamination, so before using chlorine on your rainwater tank, get a licensed professional to inspect the tank. If your rainwater is slightly discoloured or has an odd odour, then the chances of the rainwater being infected are high. Chlorine can be administered in two forms, either as a powder or as tablets. It is extremely effective, with under a teaspoon of chlorine being able to eradicate most impurities.


Boiling water is an effective form of purifying rainwater if you plan on using it for human consumption. Boiling is not effective if your rainwater has a serious contamination problem, but since rainwater is generally very clean, boiling is acceptable if your rainwater lacks any serious contaminants (serious contaminants should only show up in your rainwater if an animal decays in the water, or a harmful chemical gets into the water somehow).

UV light systems

Ultraviolet light can be used to purify water. This is actually a great way to purify rainwater, because UV light systems are easy to maintain and do not require you to add chemicals to the rainwater. If you plan to install a UV light system, make sure you also install a sensor telling you whether the UV light system is operational or not. UV light systems need to have their batteries replaced every six months or every year depending on the model.

Some common rainwater tank issues

Here are some common issues that you as a rainwater tank owner should be prepared to deal with.

Mosquito contamination

If you notice that your rainwater tank has become a breeding ground for mosquitoes, you should either call a professional to remove the mosquitoes, or treat your rainwater tank with a bit of kerosene to kill the mosquitoes (this is the solution recommended by the government). Afterwards, repair the hole in your mesh that the mosquitoes got through.

Lead contamination

This is a problem for those who do not regularly clean their gutters, or have painted their roof with paint containing lead. If your roof was painted with lead paint, there is not much you can do. If the problem has originated from your gutters (when the rainwater touches the leaves in your gutter, the pH level is lowered and the metal can corrode after a long period), then make sure you clean your gutters and install some leave protectors on your gutters.

Fecal contamination

Sometimes animals can release fecal matter into the rainwater, the most common suspect is birds hanging over the rainwater from nearby branches. So, make sure that you are regularly pruning branches that hang over your rainwater tank.

If you are interested in a complete guide, the government of Australia has released a complete guide on the usage and maintenance of rainwater tanks, you can access it here