I never thought I'd ever make lasagna in a slow cooker! This is exceptional! I did opt to use my own spaghetti sauce, but there isn't anything wrong in using the bottled. I just prefer mine. I used the same amounts. You may choose to use some Italian sausage along with the ground beef. If so, just remove the casing from the sausage, break it up and cook it right along with the ground beef.
**Note** You may want to check your lasagna after about 3 1/2 hours, don't cook it too long.