I've never grown any of those strains, so I can't speak in that regard. However, the rest of your setup looks reasonable.
The plants look healthy, so you just have to be patient. Likely, the roots will gain some ground, then the plants will start to take off. I wouldn't change anything right now at all.
You didn't say what your water's pH is though. Do you have a pH tester? If not, get one, even a cheap one when you upgrade your lamp.
Even these cheap ones will do the job. If you can afford to, also get a pH calibration kit. They generally come in a two-liquid pack.
The plants look healthy, so you just have to be patient. Likely, the roots will gain some ground, then the plants will start to take off. I wouldn't change anything right now at all.
You didn't say what your water's pH is though. Do you have a pH tester? If not, get one, even a cheap one when you upgrade your lamp.
Even these cheap ones will do the job. If you can afford to, also get a pH calibration kit. They generally come in a two-liquid pack.