<p>Overhead tank cleaning involves draining the tank, removing sludge with a vacuum, scrubbing inner surfaces with brushes and cleaning solutions (like mild detergent or bleaching powder), rinsing thoroughly, and disinfecting (optional) for safe water storage, often done by professional services using specialized pumps and equipment for hygiene and efficiency.&nbsp;<br><br><strong>Step-by-Step Process (Professional or DIY)</strong></p><ol><li><strong>Shut Off Supply &amp; Drain:</strong> Turn off the inlet, open the outlet, and drain most water, leaving some for sludge.</li><li><strong>Remove Sludge:</strong> Use a vacuum pump or scoop to remove sediment from the bottom.</li><li><strong>Scrub Surfaces:</strong> Clean walls, floor, and ceiling with a stiff brush, long pole, or high-pressure jet, using detergents or mild bleach.</li><li><strong>Rinse:</strong> Flush out all dirt and cleaning residue with clean water.</li><li><strong>Disinfect (Optional):</strong> Apply a chlorine solution (like bleach) and let it sit, then rinse again to kill bacteria.</li><li><strong>Refill &amp; Test:</strong> Refill the tank and test water quality if for drinking.&nbsp;</li></ol><p><strong>Why Get it Done Professionally?</strong></p><ul><li><strong>Expertise:</strong> Professionals use proper tools like pumps and vacuum cleaners.</li><li><strong>Safety:</strong> Prevents contamination and ensures thorough cleaning, especially for large tanks.</li><li><strong>Efficiency:</strong> Faster, more thorough cleaning, sometimes without fully draining the tank (using specialized methods).</li></ul>