I have had a Landpride scarifier SF2566 for 8 years. Originally used behind a JD 5200 (8500 lb operating weight) I could pull all 6 shanks to a depth of 12 inches. I have loaned it out to 3 neighbors and found that a good rule of thumb is the following...you need 1,000 lbs of tractor weight for each shank's max depth of 12 inches. This is in soil that has the usual mix of sod, rocks and tree 'hair' roots. In other words, a 2500 lb tractor can pull 2 or possibly 3 max shanks. The PDF to the User Manual follows and you can find operating techniques and things to avoid. One thing to check is that max lift height of your 3-point allows the beam carrying the shanks to be above ground level with the depth of shank setting you need. Otherwise you will have to shorten the shank setting to get going.