To be able to thoroughly clean items, the ultrasonic cleaning solution should always be capable of removing contaminants. But that does not mean that the cleaning solution should be fresh every cleaning session. The ultrasonic cleaning solution should be changed regularly in industrial cleaning. In cleaning medical and dental tools, the cleaning solution can be reused but should be changed every few hours.
Although reusing ultrasonic cleaning solution is fine, the solution has to be checked after every cleaning session. This is to be sure that the bath is still capable of removing dirt. If there is visible debris in the solution, the solution has to be changed. It is also important to thoroughly check the items cleaned and see if they are properly cleaned. If there is noticeable dirt on the objects, the solution in the ultrasonic cleaner has to be thrown away and replaced with a fresh bath.