For many years, ordinary households have relied on a simple visual way to judge the size of a water tank. The basic standard has been easy to understand: household water tanks start from around 1,000 litres, with larger tanks increasing in clear 1,000-litre steps—2,000 litres, 3,000 litres, and so on. Because a genuine 2,000-litre tank has roughly twice the volume of a 1,000-litre tank, the difference in physical size has normally been easy for consumers to see. This gave ordinary buyers a simple form of protection. They did not need special equipment to have a reasonable idea of whether the tank they were buying was really the size claimed by the seller.
That simple protection is now being threatened by the way some plastic and fiberglass tanks are being designed and sold. Some manufacturers can change the shape of a tank without greatly increasing its actual capacity. This is particularly possible with fiberglass tanks, where manufacturers can change the mould, height, width, shape, wall thickness, and outer design. A tank can therefore be made taller, narrower, wider at certain points, tapered, or covered with external ribs so that it looks much larger than it really is. A 1,000-litre tank may therefore be made to look like a much larger tank. Consumers may then pay a higher price for a tank that does not actually hold the amount of water they were promised. This is not simply a matter of attractive design. When the appearance of a tank is deliberately used to create a false impression about its capacity, it becomes a serious form of consumer deception.
This kind of manipulation also raises an important ethical and religious question. Islam has given special importance to honesty in weights and measures. The Qur’an devotes an entire chapter, Surah Al-Mutaffifin (The Defrauders), to condemning people who cheat others in commercial measurements. It warns: “Woe to those who give less [than due], who, when they take a measure from people, take in full. But if they give by measure or by weight to them, they cause loss.” (Qur’an 83:1–3). Selling a tank with a false or misleading capacity claim is a modern example of tatfeef—giving people less than what they are led to believe they are buying. The warning in the Qur’an is therefore not only about obeying a market rule. It also reminds traders that honesty in measurement is a matter of faith, moral responsibility, and accountability before God.
The financial harm does not stop when the consumer buys the tank. The same deception can continue every time the household buys water. Water tankers commonly charge according to the amount of water delivered. If a household tank is advertised or labelled as holding more water than it actually can, the consumer may pay for a larger capacity even though the tank cannot physically receive that amount. The household therefore loses money twice: first when it pays too much for the tank itself, and then repeatedly when it pays water suppliers for a volume that the tank cannot actually hold. What appears to be a one-time deception can therefore become a continuing financial loss for the family.
An ordinary person buying a water tank should not have to become a measurement expert to protect themselves. Consumers should not be expected to carry special equipment or calculate complicated geometric formulas to determine the true capacity of a fiberglass tank. They should not have to measure the thickness of the walls or work out the internal volume of a specially shaped mold. The responsibility for giving an accurate measurement must rest with the manufacturer and the seller. The market therefore needs clear and reliable volume standards. Whether a tank is made from plastic or fiberglass, its actual capacity should be verified and clearly stated according to recognised measurement standards, beginning with the 1,000-litre baseline and using clear, verifiable capacity categories.
This problem requires urgent action from municipal authorities, standards authorities, and consumer-protection bodies. Local authorities of our cities should establish clear rules requiring manufacturers to meet verified capacity standards and should prohibit designs that deliberately create a misleading impression about a tank’s actual volume. The verified capacity should also be permanently marked or molded into the tank itself, rather than being shown only on an adhesive label that can easily be changed or replaced. Inspectors should regularly check the actual volume of tanks produced by manufacturers and the capacity used by commercial water suppliers. Businesses that deliberately sell tanks with false capacity claims should face serious penalties. Fair trade, public trust, consumer protection, and religious ethics all depend on honest measurement. The rule should therefore be simple and firm: a water tank must be sold according to its officially verified capacity—not according to how large its shape makes it appear.
Written by Mohamed Ahmed Ba’alul
