How to clean a water tank
A clean tank is the first step to safe water at home. This guide takes you through draining, scrubbing, and rinsing your overhead or underground tank, then treating the fresh water so it stays safe to drink. It applies to the tanks found on most homes in Pakistan.
Why it matters in Pakistan
Overhead and underground tanks sit for days between fills, and in the heat they warm up, which lets a slimy film, called biofilm, and bacteria grow on the walls and floor. Dust, insects, and sediment settle in too. Cleaning the tank on a regular schedule, and treating the water once it is refilled, keeps what comes out of the tap safe for your family.
- 1
Drain the tank
Turn off the inlet and empty the tank completely, using the outlet or a pump so no old water is left standing. Work when the tank is already low, so you waste as little water as possible.
- 2
Scrub the walls and floor
With the tank empty, scrub every wall, the floor, and the corners with a stiff brush to lift the film and any settled dirt. Reach into the corners and around the inlet and outlet, where growth collects most.
- 3
Rinse out the dirt
Rinse the loosened dirt down to the outlet and flush it right out, then rinse again until the water runs clear and the floor is clean to the touch. Remove any sediment left in the base.
- 4
Let it refill with clean water
Close the outlet, open the inlet, and let the tank fill with fresh water. Check that the lid seals properly, so dust and insects cannot get back in between cleanings.
- 5
Treat the stored water with Aquatabs
Once the tank is full, treat the stored water with Aquatabs so it stays safe to drink. Use the tablet size and amount given on the pack for your tank, and let it stand for about thirty minutes. The water calculator works out the right amount for your tank size, and the large tank sizes are in the shop.
A few tips
- Clean the tank on a regular schedule, and more often in the summer heat and after floods or a dirty supply.
- Wear gloves, keep the space ventilated, and take care on ladders and around an open underground tank.
- A well sealed lid keeps out dust, insects, and sunlight between cleanings, so the water stays cleaner for longer.