Prepare the cleaning solution in an empty slop tank or in a tank immediately adjacent to the pump chamber. The cleaning solution is prepared with UNITEDCHEM-RUST at 5%. Afterwards, the solution is circulated in the tank with the aid of the heater and tank washing system. The chemical solution returns to the slop tank from the tank with the leaching cycle tube. It is not usually possible to re-circulate the solution through the tank washing heater (to keep the temperature of the solution constant) without making a temporary connection between the chemical solution preparation tank and the tank washing pump. The capacities of slop tanks, pipelines and pumps must be calculated carefully so that a sufficient volumetric quantity can be maintained in the continuous circulation of the chemical solution. Depending on the condition and size of the tanks to be cleaned, besides the amount of chemical solution, only a single chemical solution will generally clean the stains on only 2 tanks. After cleaning, the tanks are rinsed with fresh water and the exact result is obtained. Circulation time is 2-3 hours.