Yellowing, cant figure it out...

O.k guys, hello to all.

Ive got some yellowing on 1 of the main tips of 1 of my plants and have checked the stickys on here but cant work out what the problem is...

Am about 2-3 weeks into flowering and using a 250w HPS in a grow tent. Ive got a fan blowing fresh air in but its blowing right onto the yellowing part. Do plants suffer from wind burn?

Anyway the picture is below, any help is appreciated.

Peace out

Yes they do. And that is probaly the problem because otherwise those are looking good.

yes air blowing right on yer plants will dry them out especialy if its hot air!!
try giving some Nitrogen .......worm poop
....or some mexican bat shit
good luck

It could be a leaf blight fungus, it causes similar damage but it normally attacks lower leaves, and works its way up. If it starts spreading after u move the fan u could have a problem.

I thought it could be the fan.... Nice one lads!