Neon light is not enough light to grow your plants period.

If you want to start them in veg early then use CFL once they are large enough (like turtle said) take a clone from each plant and mark them so you know what plant they came from. Root those clones and flower them once the clone showes it's sex you know what the parent it came from is.

It's not good to flower them and then take them back to veg cycle. You will not have as much yeld as you want if you do. They will go back and flower early and the growth will stunt. Once the plant is in a flower cycle it puts it energy into making flowers and not growing as much as the veg cycle.

Cool bulbs (6500k) are best for seedling, cloning and vegetative growth.

(4000k) Are best for general growth and flowering


That is why.