Stems showing Purple

Shag is right. Babies look good. Cheers

Hi there, If you think they are overwatering, they will show not only purple stem but also early yellowing from bottom.So I think you should still monitoring their responses.Always adjust your pH around 6.5 and check run off.Maintain dry/wet circle between each watering.If you are not planning to grow two plants in one pot, I recommend you to separate them as soon as possible.Happy growing... ✌️

If you use as much water as you say, it hardly can be overwatering. The reason could be wrong pH or low night temperature (64 degrees Fahrenheit is admissible, but somewhat chilly) Also, if stems are red only where light touches them, then the lamp is too powerful and should be kept farther during first weeks. Red stems can sometimes be the sign of a Phosporus deficiency (in this case red color takes over lower parts first, progressing upwards), but the deficiency itself often comes from wrong pH level.