Generally speaking, the 2.5 gallon container of The Classic 18 - 3 - 6 with 50% SRN will treat about 16,000 - 45,000 sq ft depending on what you are treating (ie Greens, Fairways, Sod, etc).
Yes, this is a concentrated fertilizer. The mix rate of Classic 18-3-6 with 50% SRN will vary depending on where you are treating. Please see the label for complete application instructions.
The Classic 18 - 3 - 6 with 50% SRN would not be recommended to apply in a hose end as the rate is not set per gallon but is per area depending on the amount of nitrogen you need to apply. Please refer to the product label for complete instructions
For General Turf Applications using The Classic 18 - 3 - 6 with 50% SRN, the product label recommends applying ¼ to ¾ lbs of Nitrogen per 1000 sq ft which breaks down to 17 fl oz to 50 fl oz per 1000 sq ft. Applications every 4-10 weeks (or as needed) per 1000 sq ft in 1 to 2 gallons of water are recommended.
The Classic 18 - 3 - 6 with 50% SRN does need a surfactant added. The label states to add one once it has been mixed with water.
The Classic 18 - 3 - 6 with 50% SRN is safe on Kentucky Blue Grass and canbe used if the nutrients it provides are what is needed in your lawn. As long as you keep pets/children out of the area while you treat and until the product has had time to completely dry or settle it is safe for pets and people to return and resume normal activity typically after 4-6 hours.
The Classic 18 - 3 - 6 with 50% SRN does not need to be watered in as it is diluted with water for spraying at application.