Can you clean a water tank yourself, or should you call a professional?

When DIY is reasonable, and when it is not

Plenty of people in Gurugram clean their own rooftop tank, and for a small tank that is in good shape, that can be fine. What matters is the type of tank and whether you can do it without climbing inside.

• Reasonable to DIY: a small rooftop plastic tank, roughly 500 to 1,000 L, with a wide lid you can reach into from outside, on a roof with a parapet or railing.
• Better left to a pro: larger rooftop tanks where you cannot reach the floor from the lid, tanks on sloping or unprotected roofs, tanks with thick black sludge, and anything you would need to climb into.
• Never DIY by entering: underground sumps. A sump is a confined space with little fresh air. Do not go down into one, and do not let a helper or a casual labourer go down either.

Safe DIY steps for a small rooftop plastic tank

If your tank fits the first group, this is a careful way to do it without getting inside:

1. Plan the timing. Pick a cool morning. Turn off the motor or inlet the night before and store enough water in buckets for the day.
2. Drain the tank. Open the drain valve if it has one, or run the bathroom taps until it is nearly empty. Use the last of the water for mopping or plants rather than wasting it.
3. Scoop out sediment. Use a long-handled mug or a wet-dry vacuum to lift the sludge from the floor. Stand outside the tank and reach in through the lid; do not lean your whole body over the opening.
4. Scrub the walls. Use a long-handled soft brush or sponge mop. Avoid wire brushes and harsh scouring, which scratch the plastic and give algae more places to grip.
5. Rinse thoroughly. Rinse with clean water two or three times, draining each time, until the water runs clear.
6. Disinfect carefully, or skip it. If you use a disinfectant, only use one that is labelled safe for drinking water tanks, follow the label exactly, and flush well afterwards. Never mix cleaning products, and never use toilet or floor cleaners in a water tank.
7. Close up properly. Check the lid seals well, refill, and run each tap for a minute.

Work with a second person nearby, wear grippy footwear, and do not do this on a wet or slippery roof.

What DIY usually misses

Home cleaning can make a tank look better, but a few things are hard to do with a mug and a brush:

• Getting all the fine silt off the floor, especially in corners and around the outlet.
• Removing algae and slime from the underside of the lid and the top band of the wall.
• Removing all the dirty rinse water so it does not flow into your pipes.
• Doing anything about the sump, which is usually the source of the sludge in the first place.

A professional no-entry clean uses a sludge suction pump and a high-pressure jet for exactly these spots. Our guide to the water tank cleaning process walks through each step.

Why underground sumps need a professional

Every year there are news reports from across India of people collapsing inside tanks, sumps and pits. Air in a closed underground space can be low on oxygen or hold harmful gases, and it is not something you can judge by smell. If one person collapses, others who climb in to help are at risk too.

For sumps, the safe option is cleaning from the manhole with long suction hoses and jet lances, so nobody goes down. Read more on the underground tank cleaning page and in our sump safety guide.

Happy to DIY the rooftop tank but want the sump done safely? Or want both off your list? Send your tank sizes through the free quote form and we will reply on WhatsApp with a fixed quote including GST. No advance, pay after the job.

Questions