Does Light Harm Roots?

Greetings All...

This is my first post but I have been enjoying all of these threads for several weeks now. CHEERS and thanks for all the great info!

Anyways, if roots are exposed to light (say by growing out the sidewalls of a net pot) will they be harmed?

thanks again,
sp

yes, light is no good for roots

Normally, in nature most plants would be grown in soil with the roots hidden from the sun. So, when using hydro of any kind it's best to use a dark, opaque tank/terrarium to shade the roots from the HIDs. Even though hydro is a man-made ecosystem you are still using the basic laws of nature.
Nutrient Uptake through the roots, some foliar feeding, and of course photosynthesis.

When arranging light shielding for roots and for tubes carrying nutrient solutions, bear in mind that with high-intensity lighting, plastics which are black in colour might not be all that opaque.

I've bought panda film (admittedly cheap stuff) which looked pretty opaque in the shop but you could see the outline of a 400W HPS tube through the stuff when it was hung up. Grrr.