A Guide to Water Tank Cleaning

Water tank cleaning may seem like an arduous task but they can be dangerous if not cared for correctly. These tanks must be cleaned and disinfected regularly or those using the water from them could end up quite ill.

How to clean a water tank

Drain the tank:

Before you start cleaning, you need to drain all the water from the tank. You can do this by turning off the valve that supplies water to the tank and opening a tap near the tank to let the water drain out.

Clean the inside of the tank:

Once the tank is empty, it’s time to start cleaning inside. For best results, use a commercial tank cleaning solution. Be sure to wear gloves and a mask to protect yourself from any chemicals you may be using.

Rinse the tank:

Once you’ve finished scrubbing the inside of the tank, it’s important to thoroughly rinse it to remove any residue. You can use a hose to rinse the inside of the tank, making sure to get into all the corners and crevices. Failing to rinse all of the cleaning solution out will contaminate the water, so be sure to take extra care. 

Clean the outside of the tank:

While you’re cleaning the inside of the tank, you should also take the time to clean the outside. Use a hose to wash off any dirt or algae that may have accumulated on the exterior of the tank.

Sanitize the tank:

After you’ve finished cleaning the inside and outside of the tank thoroughly, it’s important to sanitize it to kill any remaining bacteria or germs. You can use a commercial water tank sanitizer. However, be sure to follow the instructions on the product or solution you’re using to ensure proper sanitization.

Refill the tank:

Once you’ve finished cleaning and sanitizing the tank, it’s time to refill it. Turn the valve back on and let the tank refill with fresh, clean water.

Disinfection of the Water

Water tank cleaning may be hard work, but it’s the disinfection and chlorination of the water that requires care. You don’t want to overload it with chemicals, so test the pH of the water, then follow the instructions on your chlorination kit to chlorinate it. This should only be done once the tank is full.

As soon as the water has been properly chlorinated and retested to ensure it is correctly done, open the outlet so that water can flow through all the pipes.

Finally, neutralise the chlorine with sodium thiosulphate if necessary and let this drain through the system. At this point, your water should test the same as the mains water and should be essentially chlorine free (0.5-0.1PPM). Keep track of this information.

Why Water Tanks Can Be Dangerous

The main issue with a water tank is that the water is not moving. Stagnant water is exactly where bacteria can breed and overpopulate. This happens most often in tanks that are either very large or rarely used. Bacteria such as Legionella can develop rapidly in the right conditions, but it’s not just bacteria that will accumulate.

Debris can find its way into the tank, providing food for bacteria, as well as new bacteria. However, it can also bring with it rust and sediment, which can be damaging to pipes or cause blockages If the tank is not properly sealed, it’s even possible for plant matter and rodents to find their way in, further contaminating the water.

It’s natural to see structural issues over time as well, such as cracks, leaks, or corrosion. These issues can cause the tank to fail, potentially leading to water damage or even collapse. By staying up to date on your water tank cleaning, you’ll be able to identify any minor issues before they lead to more serious damages. 

Regular Water Tank Cleaning is Important

Without regular water tank cleaning, your tank could harbour many unpleasant things. There should be a specific schedule to disinfect and clean the tank properly. This means flushing the tank first and then isolating the tank inlet so that you can drain the entire tank. It will need to be completely emptied.

You should consider photographing before and after draining, as part of your records.

Every part of the interior surface must be cleaned. You can do this by getting inside the tank (make sure there are always two people present in case one has a problem) and scraping all the debris from the walls. Use a wet vac to remove any excess debris and dirt from walls and floor.

At this point, you should check over the tank interior to see if there are any issues. Look for missing filters, damage, cracks, or corrosion and rust. Fix these and then flush the tank.

Water Tank Cleaning – How often should I do it?

The frequency of water tank cleaning will depend on several factors, including the size of the tank, the water source, and the quality of the water. However, the experts at H2O Comply recommend that to maintain excellent water hygiene that your water tank is cleaned every 6-12 months. 

At H2O Comply, we offer UKAS-accredited Legionella water testing, monitoring, sampling and microbiological laboratory analysis, undertaking an extensive range of testing services. Routine water sampling is a cost-effective tool in helping to determine the overall quality of the water within your water system. Implementing a regular sampling schedule will help to ensure the quality of the water on your premises and manage the risks associated with Legionella. To ensure you water tank is up to standard, contact us today.