Are you planning on putting these plants outside? Cannabis is a very light hungry plant that requires ~200 watts of quality lighting per plant for a medium sized indoor grow. It’s going to cost a fortune to get lighting that will flower that many plants indoors.
T5 bulbs aren’t going to work for you. The current standard in cannabis lighting are lights built with Samsung LM301 series diodes. The LM301h is the latest and greatest, but LM301b diodes are perfectly acceptable and are only ~10% less efficient.
You just need to lower the lights. Until the plants are kissing them. That should get you to transplant time.
Second the replant them deeper too. Or at least mound up the stems a little. Solo cups would work perfectly. You can even plant them off angle to one side of the cup. Stem running a bit diagonal to shorten it up into the soil a tad more.
There is a phone app out there that measures light intensity called Photone. Light is measured in PPFD. Photone will give you that value. Expect to give your plants a minimum of 400 PPFD until you can get them outdoors. You don’t need the high-end lighting I mentioned if you are putting them outdoors in a few weeks.