A non-oxidizing, buffered disinfectant concentrate is provided to be included in a solution used to disinfect a membrane. The solution applied to the membrane is configured to have a pH that is compatible with the membrane. The disinfectant concentrate includes an aqueous solvent； a hydrotrope； a strong acid surface cleanser； a biocidal active, preferably, at least two biocidal actives； a buffer agent； and, optionally, an anionic surfactant. The biodical active may be selected to function both as a biocide and as a weak acid/buffer combination. A disinfectant solution applied to the membrane includes from about 0.1 wt% to about 3.5 wt% of this disinfectant concentrate.
