Well that's good so you just transplanted them. They still look a bit small but that may just be the angle of the picture. How did the roots look? You should see a fair bit of roots corresponding to the contour of the cup. A straggly root doesn't necessarily mean it is time to transplant. Let them build up a decent root mass. Also, if you don't have one, get yourself a PH tester for the water. Pennies well spent.