So i'm playing with a flood n drain setup. I've looked a lot of places, but I haven't seen anything covering root protection from light. Is it needed? I'm not sure how the roots will work in this system.

How I have it: net pots, filled with hydroton, plant in 1" rockwool cubes in hydroton, all on top of a coco mat square I cut to put under each pot.

I know roots+light=bad, but I'm not sure if it's an issue with the coco mats (like if the roots intertwine there and aren't exposed to the light).

Thanks!

I once grow with net pots on a flood table. Light won't hurt the roots directly but it will give algae a boost which can be bad. I would recommend wrapping the top of your table with panda film and then cut holes where you place your plants. It worked pretty good. I would recommend getting pots with holes in the bottom that way most of your roots are protected from light and algae.