29 November 2023

How often should you clean your water tank?

If you have a water tank then you will know how important it is to keep it clean. Over time, sediment and organic matter can accumulate in the bottom of your tank and if this goes unchecked, it can quickly lead to issues with the quality of your water, as well as potentially damaging both the tank itself and the pump. Keeping your water tanks properly clean and maintained is a vital step in ensuring you have access to high quality water. This is especially true if your water tank supplies water to your property for potable purposes (drinking, cooking, washing etc). Even if the water from your tank is used for non-potable purposes such as watering the garden or washing the car, it’s still important to keep your tank clean and well maintained to extend its lifespan.

So, just how often should you clean your water tank?

How often should you clean your water tank?

There is no hard and fast rule when it comes to the frequency of how often you should clean your water tank, however, like most things in life, the more frequently it is cleaned, the better. Most tank cleaning specialists will recommend getting your tank professionally cleaned and serviced at least once a year, although some will say every 2-3 years is fine.

There are others that like to get their tanks cleaned every six months, especially if it is the main water supply to your property and the water that you are drinking and cooking with.

Another key factor that will determine how often you need to clean your water tank is where the water is being sourced from. Most water tanks collect rainwater from the roof of a property which is then filtered into the tank via downpipes. The cleanliness of your roof and your gutters and downpipes will factor into how often your water tank needs to be cleaned as well as the defences you put in place such as filters and screens.

How do water tanks get cleaned?

It is highly recommended that you use a professional water tank cleaning service for the regular maintenance of your water tank, although some people do choose to clean their own water tanks.

When using a professional water tank servicing company, they will typically use a high-performance vacuum pump to remove any sludge and sediment from the bottom of your tank. This work can usually be carried out without needing to empty your water tank which can save you the cost of having to refill your tank if you choose to clean your tank yourself.

The high-performance vacuum will clean out any debris and organic matter from the bottom of your tank, helping to improve the overall water quality and ensure the water is safe for drinking, cooking with and washing.

If you do choose to clean your own water tank, you would typically need to drain the tank right down and then use a brush to loosen any debris and sludge from the bottom of the tank. This would then need to be emptied out of the scour valve and the whole tank would then need to be rinsed out to make sure it is completely clean before it gets refilled.

How to remove algae from a water tank

Algae can grow in water tanks if left unchecked and this is an important thing to keep an eye out for. Direct sunlight accelerates the growth of algae and so this is a problem that tends to be more common during the summer months. There are a few things you can do to prevent the growth of algae in your water tanks:

UV Filtration

A multi-stage filtration system, especially one that includes UV filtering is one of the best ways to prevent the growth of algae in your water tank. There are a number of filters that can be added at various stages before the water you collect in your tank comes out through the taps and the general rule is that the more filters you have, the better the quality of the water.

Dark Tanks

The colour of your water tank can play a huge role in inhibiting the growth of algae. Many of today's tanks are plastic and come in a variety of colours. Whilst it is tempting to get a colour that matches the exterior of your house, generally, the darker the tank, the better the chance you have of restricting algae growth. By restricting the amount of light exposure on your water tank, you inhibit the growth of algae.

Chemical Treatment

Some people choose to treat their water tanks with chemicals in order to ensure the quality of their drinking water. Chemical treatments can include chlorine or bleach, neither of which sounds like a great option for drinking water but that is both perfectly safe when delivered in the correct proportions. It is important that you know how much water is in your tank so it can be treated properly – if you get the proportions wrong, you can make the water more harmful to drink.

How to clean an underground water tank

Cleaning an underground water tank is not too dissimilar to one stored above ground and again, it is advised to bring in a professional water tank cleaning company to clean your underground water tank. They will use a high-performance vacuum cleaner to clean out the tank, although if you want to clean the tank yourself, you would do so in the same way by using a hard bristle brush to remove any debris from the sides of the tank and to loosen the sludge from the bottom of the tank before draining, rinsing and draining again until the tank is free from sludge and debris.

When is the best time to clean my water tank?

If you are using a professional cleaning company, there is no right or wrong time to clean your water tank as they will not need to drain your tank in order to clean it. If you are cleaning your tank yourself, the end of the summer is the best time to clean your tank as this is the time when it is most likely to be at its emptiest making it easier to clean and a time when you will waste the least amount of water as you will need to empty it out to clean it yourself.


When it comes to cleaning your water tank, we recommend getting a professional service and clean at least once a year depending on how clean your roof and gutters are. In addition, you should look to clean out your gutters every 2-3 months to reduce the amount of debris and organic matter that has a chance of washing into your water tank.

It’s important to understand how much water is in your tank if you are going to treat it with chemicals. At Smart Water, we have engineered the most advanced tank level indicator available that now offers full cloud connectivity. 

Easy to install yourself, your Smart Water tank indicator provides you with all the information you need from our app or from one of our LCD displays. Find out how much water you consume on average from your tank, accurate pressure data and estimates on when your tank will run out of water based on current usage.

Find out more about our range of products or check out our FAQs for more information.