Yes, you can use 63 oz of Drive XLR8 Herbicide Crabgrass Killer in 20 gallons of water to cover 1 acre and not need to refil your tank. That is how the product label states to use.
Drive XLR8 Herbicide should not be used in temperatures above 80 degrees Fahrenheit. You will use 29 fl. oz. in 20 gallons of water. The rate is 1.45 fl. oz. per gallon of water.
The first thing you need to know when using an herbicide such as Drive XLR8 Herbicide is that the exact amount of water you dilute it with is not important. It is only important to make sure you are using the correct amount of product per 1,000 sq ft of lawn. Use too much and you risk damaging your lawn, use too little and you will not get adequate results. You will need to use 1.45 oz per 1,000 sq ft . To decide how much water you want to use, you should mark a 1,000 sq ft area, fill your sprayer with water ONLY, and start walking and spraying just as if you were doing the actual application of herbicide. When you are done walking and spraying the 1,000 sq ft area note how much water it took you to spray that area, and that is the amount you will want to mix 1.45 oz of product with for each 1,000 sq ft area that needs to be treated. You will need to make sure treated areas are irrigated with at least 1/2 inch of water (either by rainfall or by sprinkler) following the application.
Drive XLR8 can take up to 3 weeks to see full results on targeted weeds and a second appliation may be needed for more established weeds. Keep in mind, for best results, applications should be applied to listed weeds when they are young and actively growing and temperatures are between 65-85 degrees. For actively growing crabgrass, Drive XLR8 is mixed at 1.45 fl oz per 1000 sq ft along with adding 0.16 - 0.48 fl. oz Duo Stick per gallon of water. If only treating 500 sq ft, you would cut those rates in half, mixing Drive XLR8 at 0.72 fl oz in one gallon of water along with the 0.16 to 0.48 fl oz of Duo Stick Surfactant.
It is important to follow the recommended rates per the product label and not overmix or overtreat to avoid burning or injury to your turfgrass. You may see some discoloration, burning or wilting of your turfgrass as the rate applied of 2 fl oz Drive + 1 fl oz Surfactant over 500 sq ft is double the labeled rate.
Drive XLR8 Herbicide Crabgrass Killer is applied at 1.45 fl oz per gallon of water. The mixing ratio of DyneAmic Surfactant is 1-2 teaspoons of per gallon of water.