How to Clean Bathtubs, Sinks, and Washbasins

Prepare a cleaning solution by mixing sulfuric acid (25–50 grams per 1 liter of water) with copper sulfate, then wipe the bathtub or sink with a cloth wrapped around a stick. Rinse the bathtub or sink with water afterward. Clean washbasins the same way using a hydrochloric acid solution (100 grams per 1 liter of water).