MedUs_0oanswered grow question 4 years ago according to my humble opinion and vision, it seems like mine with the other days, a difference instead of my internal growth with the lamp, so a little bigger or less does not make a difference, the little difference you noticed it can be given by a lot of variables such as temperature, light absorbed by nutrients and oxygen etc. etc. so I advise you not to worry and not to be in a hurry and not to stress too much, it has its time and more time you can wait without interfering too much better and, from what little I learned to learn and that if you want a good product you need with a lot of patience, try to check the pH of the soil which is perhaps one of the most important things, but perhaps this thing you can correct slowly and always a little at a time. I wish you well for a good production.