Water Tank Cleaning Services in Karachi
Pest Tech provides water tank cleaning services in Karachi for underground sumps and overhead tanks. Our trained crew drains the tank, removes sludge, scrubs and pressure-washes the walls, disinfects with a measured chlorine dose and checks the residual before refilling. Most homes should clean both tanks every six months; tanker-fed homes every three to four.
Estimated starting price — final price confirmed after free inspection: from Rs 1,800 per tank.
Signs your water tank needs cleaning
Karachi tanks fill with silt, sand, algae and bacteria faster than most families expect, because line water, tanker water and boring water each bring something in. These are the signs it is time to clean:
- Water has a smell, a metallic taste or a yellow, brown or green tint
- Grit or slime in taps, shower heads, filters or the geyser
- Filter cartridges clogging faster than usual
- Green water or a green film inside a sun-exposed plastic tank
- Mosquito larvae, lizards or insects near the lid or overflow
- More than six months since the last cleaning — or water stood in the tank after monsoon seepage
Our 7-step water tank cleaning process
- 01
Inspect
We check the tank, lid, inlet, overflow and pump, look for cracks and seepage, and confirm the tank type and size before quoting.
- 02
Drain or transfer
Usable water is pumped out or transferred, and the pump is isolated so nothing is pushed up to the overhead tank during cleaning.
- 03
Remove sludge
Settled silt and sludge are removed manually and with a submersible pump — the heaviest layer is usually in the underground sump.
- 04
Scrub and pressure-wash
Walls, floor and ceiling are scrubbed and pressure-washed to break up the biofilm that keeps re-contaminating clean water.
- 05
Vacuum
Dirty rinse water is pumped and vacuumed out, so loosened sediment does not settle back on the floor.
- 06
Disinfect with chlorine
A measured chlorine solution (sodium or calcium hypochlorite) is applied and left for the full contact time.
- 07
Rinse, refill and check
The tank is rinsed, refilled and the chlorine residual is checked before the tank goes back into use. We also check the lid and vents.
Why Karachi water tanks get dirty
Most Karachi homes store water twice: an underground sump that fills from the line or a tanker, and an overhead tank that the pump fills from the sump. Each supply brings something different:
| Supply | What it brings in | Where it settles |
|---|---|---|
| KWSC line water after supply gaps | Silt, rust, pipe residue | Underground sump floor |
| Tanker water | Sand, organic matter, unknown source quality | Underground sump |
| Boring (groundwater) | Dissolved salts, iron, hardness | Walls and pipes as scale |
| Open or broken lids | Dust, leaves, lizards, insects | Overhead tanks |
| Sunlight through thin plastic | Algae (green water) | Plastic and fibre overhead tanks |
| Cracks and seepage | Ground water, sometimes sewage | Older RCC sumps |
Underground sumps collect the heaviest sludge because they fill first. Overhead tanks get less silt but more dust, heat and algae. Homes that rely on tankers — common in parts of DHA, Clifton, Scheme 33 and Malir — build up sediment faster.
What water testing in Karachi has found
The Pakistan Council of Research in Water Resources (PCRWR) has tested Karachi's water repeatedly. In testing reported by Dawn, 107 of 118 Karachi samples (90.7%) were unsafe; 88.1% contained coliform bacteria and 33.4% contained E. coli. PCRWR's Drinking Water Quality in Pakistan 2021 report found 93% of the Karachi sources it monitored unsafe, mainly because of bacteria.
Your home tank sits at the end of that chain. If contaminated water goes in and the tank is never cleaned, bacteria have a warm, dark place to multiply. Boiling or filtering at the tap helps, but it does not remove the sludge and biofilm inside the tank — cleaning the source is the lasting fix. The World Health Organization's drinking-water fact sheet explains the diseases linked to unsafe water, and its technical note on cleaning water storage tanks sets out the clean → disinfect → flush sequence we follow.
Homes, buildings and commercial tanks
- Houses and flats — usually one underground sump and one overhead tank. Clean both in the same visit, otherwise sludge from the sump re-contaminates a freshly cleaned overhead tank within days. See underground tank cleaning and overhead tank cleaning.
- Apartment buildings and societies — large shared sumps and several rooftop tanks. We schedule with the union or management so residents get notice and supply is restored the same day where possible.
- Commercial sites — hospitals, schools, restaurants and factories need cleaning on a fixed schedule and a written record of each visit for inspections.
After floods, seepage or a new installation, a tank may need disinfection and chlorination on its own.
How often to clean your water tank
| Situation | Recommended frequency |
|---|---|
| Line-water home, good lids | Every 6 months |
| Tanker-dependent home | Every 3–4 months |
| Apartment building or society tank | Every 3–6 months |
| Restaurants, hospitals, schools | Every 3 months, with records |
| After monsoon flooding or seepage | Immediately |
Combine tank care with mosquito control in the dengue season — open tanks are a common breeding site, as our guide to mosquito breeding in water tanks explains.
Areas we serve
We clean tanks across Karachi from our base in Operative Housing Society — including DHA, Clifton, Gulshan-e-Iqbal, Gulistan-e-Johar, North Nazimabad and the industrial areas of Korangi. For a quick estimate by tank size, use the water tank cleaning cost calculator.
Safety and drinking-water hygiene
- Underground tanks are confined spaces: only our trained crew enters, with ventilation and safety gear. Never send a household helper or untrained staff into a sump.
- Chlorine is measured for the tank volume, left for the full contact time and rinsed out; the residual is checked before the tank is used for drinking water.
- Only cleaning and disinfection products suitable for drinking-water tanks are used — no household insecticides, kerosene or detergents are left in the tank.
- The pump is isolated during cleaning so dirty water is never pushed into the overhead tank or the house lines.
Water tank cleaning price in Karachi (2026)
Tank cleaning is priced per tank by size (gallons) and type, with a discount when the underground and overhead tank are cleaned together. Heavy sludge, buildings and commercial sites are adjusted after inspection. Use the calculator for an estimate; the final price is confirmed after a free inspection.
| Tank size | Estimated price (PKR) |
|---|---|
| Overhead plastic / fibre — up to 300 gal | Rs 1,800 |
| Overhead plastic / fibre — 301 gal–500 gal | Rs 2,200 |
| Overhead plastic / fibre — 501 gal–1,000 gal | Rs 2,800 |
| Overhead plastic / fibre — 1,001 gal–2,000 gal | Rs 3,800 |
| Tank size | Estimated price (PKR) |
|---|---|
| Underground RCC — up to 1,000 gal | Rs 3,500 |
| Underground RCC — 1,001 gal–2,000 gal | Rs 4,500 |
| Underground RCC — 2,001 gal–3,000 gal | Rs 5,500 |
| Underground RCC — 3,001 gal–5,000 gal | Rs 7,500 |
| Each extra 1,000 gal above 5,000 gal | +Rs 1,200 |
Every figure is an estimate until a free inspection confirms the scope of work.
Why Karachi chooses Pest Tech for water tank cleaning
Pest Tech has worked in Karachi homes, schools, restaurants and factories since 2005, so we know how line water, tankers and boring affect a tank — and we treat the tank and the mosquitoes around it as one job when needed.
Trusted by Khalid Foods, Beaconhouse School System, Dunkin' Donuts — plus thousands of Karachi homes.
Water Tank Cleaning across Karachi
We treat every district of Karachi from our base in Operative Housing Society. Popular areas:
Related guides
Related services
- Underground Tank Cleaning — RCC sumps desludged, washed and chlorinated by a trained crew.
- Overhead Tank Cleaning — Rooftop plastic, fibre and cement tanks cleaned and chlorinated.
- Tank Disinfection & Chlorination — Measured chlorination after cleaning, floods or for new tanks.
- Mosquito & Dengue Control — Larviciding, residual spray and fogging against dengue mosquitoes.
Water Tank Cleaning: frequently asked questions
Every 6 months for most homes, and every 3–4 months if you rely on tanker water or the lid does not seal. Clean immediately after monsoon flooding or seepage.
Yes. Otherwise sludge from the underground sump re-contaminates a freshly cleaned overhead tank within days.
No. The tank is rinsed after the contact time and refilled, and the residual is checked before the water is used.
A typical house with one underground and one overhead tank is usually done in one visit of a few hours; large building sumps take longer and are scheduled with management.
Not reliably. PCRWR testing has found most Karachi samples bacteriologically unsafe. Keep tanks clean and chlorinated, and boil or properly filter drinking water.
A small overhead plastic tank can be rinsed from outside without entering it, but underground sumps are confined spaces and must only be entered by a trained crew with ventilation and safety gear.
Book water tank cleaning in Karachi
Send your area and a photo of the problem — we reply with the next free inspection slot.
Mon–Sat, 9:00 AM – 7:00 PM · Free inspection · Re-treatment at no extra cost if pests return