stretching is never fine lol. that's your first problem.
your second is the higher you raise your light the more lumens are lost
so your 250 HPS becomes something like a 100w HPS yet you're paying for the wasted lummens...
you want you're branches close because that's what makes on big bud.
bud sites form at the tops of branches[also known as colas] and in between the branches and main stalk[also known as nodes]
this is where the branches start to form off the main stem.
Branches closer together allow the bud to grow into each other and become more tightly packed, thus when harvested weight more and break out fatter.
I know from experience. Stretched plants mostly = soft light bud that doesn't break out.
from looking at your picture i can see that from one node to the next is around 5 inches give or take
you want your nodes like this...
and the 25 plants at once thing is way off my 400w HPS can only light a space about 4ftx4ft
which is about 16 small plants or 8 big ones.
i suggest you read up on some of the threads on here a little more they're really is an AMAZING amount of information on here.
not saying that you're a newb or anything I'm just saying knowledge is golden my friend.
and then again we learn from are mistakes
good luck with you're grow though, either way you'll be smoking!
