A few questions from a newbie ><_<

Hello everyone at roll it up.
I'm pretty new to growing, and have a number of questions i hope someone can help me with.

I'm currently somewhere around the 6th week of flowering under 250w hps light.
I have 3 fem Forbidden Fruit plants about 3.5ft or so high. They grew wonderfully, but
I had some newbie problems with the distance of my hps light and burnt up about 30% of my large leaves. How much do you guess this will effect my yeild.
And also about how far from the tips of my plants do you think i should keep my 250w hps?

I also have 3 plants under a 200w cfl in veg. I want to sea of green these so i dont have a
a problem with space and burn my new babies. I know pretty much nothing about using sea of green and need some advice ^^.

shouldnt hurt to much since its natural for a palnts bigger and lower leaves to die during budding as your plant uses less nitro and is dying in a sense and getting mature..if it was burning them from where u had it then try moving it 6in. further away .

thanks cmack that put my mind at a little ease.
Can anyone tell me how big i want the holes on my screen or net to be for sea of green?