You shouldn't have to use the trio till around the 5 week depending on how you have been water. Start with a quarter the recommended dose on the schedule, you should go by what your plants tell you for the most part, I like to push a little extra nutrient on them till is see a small amount of tip burn then back off more rather then underfeeding them, good medium color green is healthy.
The amount shouldn't be to different between to autos and the photos just watch them and keep it in mind.