A method for dynamic dosing of disinfectant solution in a medical device reprocessing system, comprising: (a) calculating a volume of an initial dose of concentrated disinfectant solution for dilution to make a first in-use disinfectant solution comprising a target concentration of disinfectant agent; (b) diluting the initial dose of concentrated disinfectant solution with diluting fluid to make the first in-use disinfectant solution comprising the target concentration of disinfectant agent; (c) applying the first in-use disinfectant solution to a first medical device; (d) measuring a concentration of the disinfectant agent in the first in-use disinfectant solution after applying it to the first medical device; (e) calculating actual concentration of the disinfectant agent in the concentrated disinfectant solution based upon the concentration of disinfectant agent in the first in-use disinfectant solution after applying it to the medical device; and (f) determining whether: (i) a volume of a second dose of concentrated disinfectant solution is increased compared to the volume of the initial dose to make a second in-use disinfectant solution comprising the target concentration of disinfectant agent, or (ii) a volume of a second dose of concentrated disinfectant solution is about the same as the volume of the initial dose to make a second in-use disinfectant solution comprising the target concentration of disinfectant agent. (a) calculating a volume of an initial dose of concentrated disinfectant solution for dilution to make a first in-use disinfectant solution comprising a target concentration of disinfectant agent; (b) diluting the initial dose of concentrated disinfectant solution with diluting fluid to make the first in-use disinfectant solution comprising the target concentration of disinfectant agent; (c) applying the first in-use disinfectant solution to a first medical device; (d) measuring a concentration of the disinfectant agent in the first in-use disinfectant solution after applying it to the first medical device; (e) calculating actual concentration of the disinfectant agent in the concentrated disinfectant solution based upon the concentration of disinfectant agent in the first in-use disinfectant solution after applying it to the medical device; and (f) determining whether: (i) a volume of a second dose of concentrated disinfectant solution is increased compared to the volume of the initial dose to make a second in-use disinfectant solution comprising the target concentration of disinfectant agent, or (ii) a volume of a second dose of concentrated disinfectant solution is about the same as the volume of the initial dose to make a second in-use disinfectant solution comprising the target concentration of disinfectant agent. (i) a volume of a second dose of concentrated disinfectant solution is increased compared to the volume of the initial dose to make a second in-use disinfectant solution comprising the target concentration of disinfectant agent, or (ii) a volume of a second dose of concentrated disinfectant solution is about the same as the volume of the initial dose to make a second in-use disinfectant solution comprising the target concentration of disinfectant agent.