How to clean a storage tank properly

Before you start

Switch off the pump and close the inlet. Tell everyone in the house that there will be no water for about four hours. Get a clean brush, a bucket, gloves, a torch and household bleach.

Step by step

1. Drain the tank fully through the washout valve.
2. Scrub walls and floor with a brush and clean water. Remove all sludge.
3. Rinse and drain again.
4. Fill with clean water and add bleach at the dose on the bottle for disinfection; leave for two hours.
5. Drain, rinse twice and refill.

After cleaning

Run every tap for a few minutes until any bleach smell has gone. If you have had germs in a past test, book a microbiological screen a week later to confirm the tank is clean.

How often

Every six months for most homes, and after any period when the lid was off or birds got in. Schools and hotels should clean quarterly.

Questions