How to Clean a Water Storage Tank and Stop Algae Growing
- Clean at least every 6 months
- Drain → scrub → rinse → disinfect (per label) → rinse → refill
- Never use toilet cleaners, acids or detergents with perfume
- Algae needs light: keep lids closed, use opaque tanks
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How Often Should Water Tanks Be Cleaned?
At least every six months for drinking water, more often if the water is dirty or the tank is open to dust, birds or rain from the roof. Clean immediately after anything falls in or the water smells or changes colour.
How to Clean a Water Storage Tank, Step by Step
- Close the inlet and drain the tank (use the water for washing or the garden).
- Scrub the walls and floor with clean water and a soft brush; never use a wire brush on plastic tanks.
- Rinse and drain the sludge out through the bottom outlet.
- Disinfect with a product made for drinking-water tanks, at the strength and contact time on its label.
- Rinse well, refill, and run the taps until any disinfectant smell is gone.
Safety: do not climb into a tank alone or into a closed tank without ventilation. Many tanks can be cleaned through the lid opening with a long-handled brush.
What Not to Use
- Toilet cleaners, acids or harsh chemicals.
- Perfumed detergents (they leave taste and residue).
- Swimming pool chemicals that are not approved for drinking water.
Why Does Algae Grow in Water Tanks, and How Do I Stop It?
Algae needs light and nutrients. Keep the lid closed and sealed, use an opaque (dark) tank, keep leaves out of gutters, and clean regularly. A tank that lets light through will keep growing algae.
Can You Drink Water From a Storage Tank?
Treat it first. Even clean tank water can pick up germs; use a purifier, boil it, or treat it with UV before drinking. See home water purifiers.
Water Tank Prices
| Product | Price |
|---|---|
| 500l Reliance water storage tank | KSh 5,500 |
| 1000L Reliance Loft Tank – No More Water Shortages! | KSh 12,500 |
| 1500L Water storage tank | KSh 11,500 |
| 2000L Water storage tank | KSh 16,500 |
| 3000L Water storage tank | KSh 24,000 |
| 4000L Water storage tank | KSh 27,500 |
| 5000L Reliance Water storage tank | KSh 36,500 |
| 6000Ltrs Water Storage Tank | KSh 43,800 |
| 8000Ltrs Water Storage Tank | KSh 56,000 |
| 10,000Ltrs Water Storage Tank | KSh 68,000 |
Current listed prices incl. VAT (updated 2 October 2026).
Related: water tank prices and tanks for refill stations.
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Frequently asked questions
How often should water tanks be cleaned?
At least every six months, and immediately after any contamination.
How do you clean a water storage tank?
Drain it, scrub with clean water and a soft brush, rinse out sludge, disinfect with a drinking-water-tank product per its label, rinse and refill.
Can I clean a water tank with Harpic or acid?
No. Toilet cleaners and acids are not safe for drinking-water tanks.
How do I stop algae growing in my water tank?
Keep light out: closed lids and an opaque tank, plus regular cleaning.
Can you drink water straight from a storage tank?
Treat it first with a purifier, boiling or UV.