You can reuse Stop Bath until the color changes from yellow to purple, which means the Indicator tells you that it is at the end of its life.
Hypo can be used until the number of film rolls or square inches [cm] has been fixed. When hypo takes twice as long to clear film as it did when the hypo was fresh, it is time to dump the hypo. Hypo check is another way to see if the hypo is exhausted.