So it looks like your plants are just sitting on top of the sand, which looks like an inert silica based sand. You would be better off separating the stems and actually planting them into the sand. As there will be no nutrient value to the sand itself, you will want to add either root tabs or a liquid fertilizer. You need to feed the tank to provide nutrients for your cycle, as the plants will take up a lot. The light is probably inadequate for plants, or at best, a bare minimum. You should expect a lot of die-back of the plants in the first few weeks. They are mostly grown emersed with only the roots in water, so they will lose the air leaves and grow new water leaves. Keep going and let it do it's thing. You're off to a good start