Glyphosate labels recommend the addition of ammonium sulfate should to counteract the effects of hard water and improve weed control. The recommended ammonium sulfate rate is generally inconvenient to use. Low rate water conditioner products are available as an alternative to ammonium sulfate with glyphosate. Pesticide applicator testimonials suggest the performance with these products has been inconsistent. Field experiments were conducted at Manhattan, Garden City, and Tribune, Kansas in 2005 through 2007 to compare the efficacy of glyphosate with ammonium sulfate or various other commercial water conditioners. Each experiment consisted of a sub-lethal (0.27 or 0.38 lb ae/a) dose of glyphosate applied in combination with the recommended application rates of the adjuvants. Water hardness and species evaluated varied by experiment. Commercial products that included an ammonium sulfate component at the equivalent rate of 1% (w/w) gave equal or slightly better control than glyphosate plus 1% (w/w) ammonium sulfate. Commercial water conditioners that did not contain ammonium sulfate, or that were applied at a much lower rate of ammonium sulfate gave less control than glyphosate with 1 or 2% (w/w) ammonium sulfate, and were often no better than glyphosate alone. Glyphosate tank mixed with the low rate water conditioners evaluated did not provide the same level of control compared to the recommended rate of ammonium sulfate.