How to Clean a Plastic Water Tank: A Complete Guide for Safe Water

Water storage tanks are essential for many households and commercial setups to ensure a steady water supply. Plastic water tanks are popular due to their durability and affordability. However, regular cleaning is crucial to prevent contamination from sediments, algae, bacteria, and other impurities that accumulate over time. This guide explains when and how to clean a plastic water tank to keep water safe and fresh.

Why Clean Your Plastic Water Tank?

Over time, dirt, algae, bacterial slime, sediment, and other contaminants settle inside water tanks. These deposits degrade water quality and may cause health risks. Regular cleaning removes these impurities, preventing foul odor, discoloration, and potential waterborne diseases. Experts recommend cleaning your plastic water tank at least once a year, though in hot climates or with poor water quality, more frequent cleaning might be needed.

Step-by-Step Process to Clean a Plastic Water Tank

1.      Preparation and Draining

• Turn off the water supply to the tank.

• Completely drain the tank water through the outlet valve.

• Use buckets to save water for other uses if needed.

• Mop up or vacuum any leftover water at the bottom

Preparation and Draining

2.      Cleaning the Interior

• Prepare a cleaning solution using mild detergent mixed with water. Do not use harsh chemicals that might leave harmful residues.

• Scrub the tank walls and bottom thoroughly using a long-handled brush or stiff bristle brush. Pay special attention to corners and crevices where biofilm tends to build up.

• For tough stains or iron deposits, an acid solution can be applied carefully, followed by detergent cleaning.

Cleaning the Interior

3.      Rinsing

• Rinse the entire tank thoroughly with clean water using a hose or pressure washer if available.

• Ensure all detergent or cleaning residues are fully washed out.

• Remove rinse water completely by draining or vacuuming.

Rinsing

4.      Disinfection

• Prepare a disinfectant solution by adding chlorine bleach to clean water (e.g., for a 500-liter tank, 2 cups of bleach).

• Fill the tank with this solution, close the lid, and leave it for 24 hours to kill bacteria and spores.

• After 24 hours, test the chlorine level with a chlorine test strip. If chlorine remains, drain the solution and rinse again before refilling.

• If no chlorine remains, the tank is safe for refilling with fresh water.

Disinfection

5.      Refilling

• Refill the tank with clean potable water.

• Check periodically for any signs of contamination or sediment build-up.

5.      Tips for Maintaining a Clean Plastic Water Tank

• Schedule cleaning at least once a year; more frequently if you live in hot climates or if water is sourced from unsafe supply.

• Cover water tanks securely to prevent leaves, insects, and animals from getting in.

• Inspect the tank regularly for cracks or damages that might allow contaminants.

• Use water testing kits post-cleaning to ensure water safety.

• Avoid using harsh chemicals such as strong acids or bleach without dilution and proper guidance—these can damage the tank or leave harmful residues.