Cleaning Ground and Roof Tanks Together in Jeddah: What Happens First and Why

In a double system the roof tank is fed from the ground tank through a pump and transfer lines, so any sediment or contamination at the source travels upward. A roof tank cleaned alone can become contaminated again after the first refill if its source was left untouched.

The opposite also holds: a clean ground tank feeding an old, sediment-filled roof tank will not guarantee clear water at the taps. The basic logic is to treat the whole system as one chain.

Details depend on the building design and the position of the pump and pipes, so the team sets the final order after inspection instead of applying one rule to everyone.

A common mistake is cleaning only the tank nearest the taps because it is easier to reach, and ignoring the source that feeds it, so complaints about colour and smell return within weeks.

The service begins by inspecting each tank type and capacity, where the access hatches are, the state of lids, float valves and valves, the pump and feed lines, and whether there are extra tanks or internal partitions.

A suitable discharge point for the water is chosen at that stage, along with the safe route to the roof tank and any need for lifting gear, lighting or ventilation.

It helps to have building plans or photos of the plumbing if you have them, and to tell the team about earlier problems such as leaks, smells or weak pressure.

The team also asks about the age and material of the tanks, because concrete, plastic and fibreglass need different methods and tools, which affects the time needed and what is checked for cracks.

Cleaning a two-tank system means a temporary water cut, so it is best to inform residents in advance, agree a suitable time, and let each household store the drinking water it needs in a safe way.

In apartment buildings, coordinate with the owner or the owners association to fix the length of the cut and to arrange consumption before the appointment so the water level is as low as possible.

We advise reading our guide on storing water during a cut before the visit so residents do not resort to improvised solutions.

Where tenants and owners live together, one shared message with the time, the expected length of the cut and a contact for emergencies avoids confusion.

Draining starts, as far as possible, with normal consumption or pumps to a safe discharge point, taking care that the water does not harm foundations, disturb neighbours or enter networks not meant for it.

Then the feed and pump lines are isolated so they do not return water to the tank during work, and power to the pump is cut for the safety of the team.

Nobody enters a tank before ventilation, lighting and safety are checked, and trained staff with suitable equipment are used.

In villas with small plots, discharge needs careful planning so water does not collect at entrances or pavements, and the time of day is agreed with the building manager to avoid disturbing passers-by.

The ground tank is cleaned because it is the source feeding the rest of the system; sediment, algae and dirt are removed from the floor and walls, and cracks, leaks, the lid and access hatches are checked.

In areas exposed to rain and flooding, mud or surface water may enter a ground tank if its lid is loose, so this part deserves special care.

After mechanical removal the tank is rinsed and the rinse water is pumped out before refilling.

Photographing the tank condition helps you compare later in the monthly check, and if you notice a musty smell or heavy algae it is worth asking why moisture, light or surface water got in so it does not return in a few months.

The roof tank faces sun and heat, so algae may form on the walls if light enters, and the lid and insulation can suffer from weather. Walls and floor are cleaned and the float valve and valves are checked.

Reaching the roof requires safety measures, especially on tall villa roofs or narrow stairs, and it should be left to trained staff.

The team reviews the lid, vents and insulation and suggests repair if needed; heat details are in our guide on roof tanks in summer.

Do not forget the pipe linking the roof tank to the building, because sediment can build up at valves and outlets and needs a special rinse during the service.

After cleaning, the tanks are filled from the approved source, then water is pumped to the roof tank and the first volume is discharged so rinse residue leaves the pipes and lines.

It is better not to use that first batch for drinking or cooking, but to flush the lines and confirm colour and smell, then open the household taps gradually.

These steps depend on the type of system, and the team explains the details on your site.

You can ask the team to note the filling time, the pumping time and the length of the first discharge, which helps in review if remarks appear later, and if the water stays cloudy after enough flushing, tell them so they can check for a source of contamination.

Ask the team for a clear description of what was done in each tank, with before and after photos where possible, and review our checklist for verifying cleaning quality after the service.

Watch tap water over the following days and note any change in colour, smell or pressure, then continue with the monthly check as described in the guide.

If a problem appears after cleaning, contact the team immediately so they can review the point of failure instead of leaving it to worsen.

In the first week, compare the water colour at the tap nearest to the tank and the one furthest away, because a difference may mean the issue is in the pipes rather than in the tank.