Your water tank is the single source of every drop of water that comes out of your taps, showers, and kitchen — and in Dubai's climate, an uncleaned rooftop tank reaches temperatures that turn it into an ideal environment for bacterial growth. The challenge is that the most dangerous contamination — Legionella bacteria — is colourless and odourless. By the time you see or smell a problem, the tank has needed cleaning for months. Here are the signs, both visible and invisible.
1. Discoloured or cloudy water from the tap. Fill a clear glass and hold it up to the light. If the water has a yellow, brown, or cloudy appearance, sediment from the bottom of the tank is being drawn into your supply lines. This happens when the tank level drops low enough for the outlet pipe to pick up settled debris.
2. A noticeable smell or taste. Musty or earthy smells suggest algae or bacterial growth. A chlorine-heavy smell that was not there before may indicate that the mains supply has increased chlorination to compensate for contamination in the distribution system — but it can also indicate biofilm in your tank reacting with incoming chlorine. Either way, investigation is warranted.
3. Reduced water pressure throughout the property. If pressure is low at every tap simultaneously, the problem is either the pump or the tank outlet. Sediment accumulation around the outlet pipe inside the tank restricts flow. This is a gradual problem — you might not notice the decline week to week, but comparing pressure to what you remember from 6 months ago often reveals a difference.
4. Visible sediment when filling a bathtub or bucket. Fill a white bucket from the tap and let it settle for a few minutes. If you see particles on the bottom, those particles came from your tank. Sediment in the tank is not acutely dangerous — it is mostly mineral scale — but it indicates the tank has not been cleaned recently and the conditions for bacterial growth (stagnant sediment layers) are present.
5. It has been more than 12 months since the last cleaning. This is the invisible sign. Dubai Municipality guidelines recommend professional cleaning every 6 months for high-risk properties and every 12 months as a minimum for standard residential properties. Even if you see no visible symptoms, annual cleaning is recommended because the most dangerous contaminants are invisible. The cleaning cost — AED 300 to 600 for a standard villa tank — is trivial compared with the health risk of contaminated water. We issue a Municipality-recognised completion certificate after every clean, which is increasingly requested by landlords and insurance companies for compliance documentation.