This video shows how to change washing water in Metos WD rack conveyor machine (tunnel dishwasher).
A clean dishwasher is a cornerstone of professional dishwashing. The rack conveyor machine should be washed daily after use. Also during the working day, both a water change and intermediate cleaning should be performed if it becomes necessary.
Check the washing result and water contamination, and always change water in your washing machine, if necessary. An excess formation of foam harming the washing result quickly reveals contamination of the washing water. Collection of foam onto the tank sieves or foam exiting from the waste pipe of the machine indicate that the washing water needs immediate changing.