Since the key ingredient for killing the grass is only 18% for the Roundup Extended Control versus 43% for the RM43, I wanted to see if mixing the RM43 to the equivalent concentration of the Roundup would yield the same results...this way the cost per gallon of the mix is almost One Third of the price ! Includes a week long time lapse to show how they did side-by-side. I added a link to Amazon if interested in getting some of the RM43 as I have an Amazon Associates account so the link helps me out by giving me credit for the referral. Hope it helps someone save some money and all the best ! Steve