What Chemical Cleans Water Tanks? A Comprehensive Guide

Water tanks are essential for storing and providing clean water to households, industries, and communities. However, over time, water tanks can accumulate sediment, debris, and bacteria that can compromise water quality and cause health hazards.

Therefore, it’s crucial to clean water tanks regularly using appropriate chemicals that can dissolve and disinfect contaminants without harming the tank’s material or leaving harmful residues.

In this article, we’ll explore the most effective chemical options for cleaning water tanks, their properties, benefits, and usage guidelines.

What Chemical Cleans Water Tanks

What Chemical Cleans Water Tanks? Types of Chemicals for Cleaning Water Tanks

Several chemicals can be used for cleaning water tanks, depending on the tank’s material, contamination level, and desired outcome. Here are some common types of chemicals and their properties:


Chlorine is a potent oxidizing agent that can kill bacteria, viruses, and fungi by breaking down their cell walls and denaturing their proteins.

  • Chlorine can also dissolve organic matter, such as algae and sediment, by oxidizing their carbon bonds.
  • Chlorine is available in various forms, such as calcium hypochlorite, sodium hypochlorite, and chlorine gas, and can be used in different concentrations and contact times depending on the tank’s condition.

Hydrogen Peroxide

  • Hydrogen peroxide is a strong oxidizing agent that can kill bacteria, viruses, and fungi by releasing oxygen atoms that react with their cell membranes and enzymes.
  • Hydrogen peroxide can also dissolve organic matter and oxidize iron and manganese deposits.
  • Hydrogen peroxide is available in various concentrations and can be mixed with other chemicals such as citric acid, sodium bicarbonate, or surfactants to enhance its cleaning power.


Acids such as hydrochloric acid, sulfuric acid, and citric acid are used to dissolve mineral deposits such as rust, scale, and lime which can clog pipes and reduce water flow.

  • Acids work by reacting with minerals and forming soluble compounds that can be flushed out with water.
  • However, acids can also corrode metal surfaces, etch concrete, and release harmful fumes, so they should be handled with caution and diluted to appropriate concentrations.


Alkalies such as sodium hydroxide and potassium hydroxide are used to dissolve organic matter such as grease, oil, and fats that can accumulate on tank surfaces and pipes.

  • Alkalies work by saponifying the organic compounds and turning them into soap-like substances that can be easily removed with water.
  • However, alkalies can also cause skin irritation, damage plants, and react with acids to produce heat and gas, so they should be handled with protective gear and diluted to appropriate concentrations.

How to Use Chemicals to Clean Water Tanks

Using chemicals to clean water tanks requires careful preparation, handling, and disposal to ensure optimal results and safety. Here are some guidelines to follow:

Preparing the Tank

Before adding any chemicals, drain the tank completely and remove any sediment, debris, or algae that can clog the cleaning solution. Use a scrub brush or pressure washer to remove any stubborn deposits, and rinse the tank thoroughly with clean water.

Make sure the tank is completely dry before adding the cleaning solution.

Mixing the Chemicals

Follow the manufacturer’s instructions for mixing the chemicals and wear appropriate protective gear such as gloves, goggles, and respirators.

  • Use a plastic or stainless-steel container to mix the chemicals, and avoid using metal containers that can react with the substances and release harmful fumes.
  • Mix the chemicals in a well-ventilated area and away from flammable materials.

Adding the Chemicals

Add the chemicals to the tank slowly and evenly, starting from the bottom and working your way up. Use a long-handled brush or mop to spread the solution evenly and reach all surfaces.

  • Make sure the solution covers the entire tank, including the corners, joints, and pipes.
  • Leave the solution in the tank for the recommended contact time, which can range from a few minutes to a few hours depending on the chemicals and the tank’s condition.

Flushing the Tank

After the contact time, drain the tank entirely and rinse it thoroughly with clean water.

  • Repeat the rinsing process several times to remove any remaining chemicals and prevent residues.
  • Use a water test kit to check the water quality and make sure it meets the desired standards.

Why Clean Water Tanks?

Before delving into the chemical solutions for cleaning water tanks, let’s understand why it’s necessary to clean them in the first place. Here are some reasons:

Preventing Bacterial Growth

Stagnant water in tanks can promote the growth of harmful bacteria such as E.coli, Salmonella, and Legionella, which can cause various diseases such as typhoid, cholera, and Legionnaires’ disease. Cleaning tanks with appropriate chemicals can kill bacteria and prevent their regrowth.

Maintaining Water Quality

As water flows through tanks, it can accumulate sediment, rust, algae, and other debris that can cloud the water and alter its taste, odor, and color. Cleaning tanks can remove these contaminants and improve water quality.

Prolonging Tank Life

Tanks made of plastic, concrete, or steel can degrade over time due to chemical reactions, corrosion, and physical stress. Cleaning tanks can remove the substances that accelerate tank degradation and prolong their lifespan.


Cleaning water tanks is a crucial task that requires the right chemicals, tools, and techniques to ensure safe and effective results. Chlorine, hydrogen peroxide, acids, and alkalies are some of the most common chemicals used for cleaning tanks, each with its properties, benefits, and risks.

Before using any chemical, make sure to read the label, follow the instructions, and wear protective gear. By keeping your water tanks clean and well-maintained, you can provide safe and healthy water to your family, customers, or community.


  • Can I use bleach to clean my water tank?

    Bleach contains chlorine and can be used to disinfect water tanks. However, make sure to use food-grade bleach and dilute it according to the instructions. Also, bleach can corrode metal surfaces and leave residues, so use it sparingly and rinse the tank thoroughly after use.

  • Can I use vinegar to clean my water tank?

    Vinegar is an acid and can dissolve mineral deposits such as lime and rust. However, vinegar is not strong enough to disinfect the tank and kill bacteria. Also, vinegar can leave a strong odor and affect the water taste, so use it only for mild cleaning purposes and rinse the tank thoroughly after use.

  • How often should I clean my water tank?

    The frequency of cleaning depends on the tank’s size, usage, and contamination level. In general, it’s recommended to clean domestic water tanks at least once a year and industrial tanks every six months or as needed. However, if you notice any changes in the water quality or smell, clean the tank immediately.

  • Can I clean my water tank myself, or do I need to hire a professional?

    You can clean your water tank yourself if you have the necessary equipment and expertise. However, if you’re not confident or have a large or complex tank, it’s better to hire a professional cleaning service that can ensure safe and thorough cleaning.

  • What are the signs of a contaminated water tank?

    The signs of a contaminated water tank include foul odor, strange taste, discolored water, sediment, algae, mold, and bacteria growth.