Get those out of solo cups and into 2+ gallon planters asap. As much as everyone wants to talk a big game, you cannot get a huge harvest off of a plant in a solo cup. I have an experiment running now, same strains 5 plants - 1 in 5 gal, 1 in 4, 1 in 3, 1 in 2, 1 in 1. All germinated and planted the same day, watered exactly the same with the exact same lighting over top. The 5 gal is about 4 and a half feet tall whereas the one in the 1 gal is about 2 feet and very slender.
On the other hand, if you just want to try solo cups - be my guest you will still get good buds, just a lot less. lol