I have some Plants on a Frugal Container made of a 2 litter bottle of Soda, The roots are in the side of the bottle and are in plain view, will the light hurt them? if not the sun but a House light using 4100K and 900 lumines
People, myself included, start and grow plants in clear glass jars filled with water all the time. Remember in grade school spouting beans or peas in a glass jar with the seed pressed against the side by a roll of construction paper so you could see the roots develop? Ever start a sweet potato plant in a jar with the roots growing into water at the bottom? Ever stuck a houseplant cutting into a jar of water to root? Those sweet potatos and houseplants grow for weeks with root exposed to light without harm.
The only possible damage is if the roots are baked dry by the sun to the point of no return. Since you don't have it in full sun, not an issue.
The light won't hurt the roots but if you are starting to see a lot of roots hugging/circling the side of the bottle and coming out of the drainage hole(s) it's time to uppot.
Alright thanks well it not so much roots but its getting close for transplanting and now that I remember yea I remember back in the day when I use to grow beans in a jar