The only thing I can think of is that you've got a potassium defficiency

Here's how to fix it

Potassium - Too much sodium (Na) displaces potassium, causing a potassium deficiency. Sources of high sodium content are: baking soda (sodium bicarbonate "pH-up"), too much manure, and the use of water-softening filters (which should not be used). If the problem is too much sodium, flush the soil. Potassium can get locked up from too much Calcium or ammonium nitrogen, and possibly cold weather as well.

I hope this helps man

Pictures will definitely help!!!
SunnyD Reviewed by SunnyD on . First Timer need help I am in about the 3rd. week of flowering and there are brown spots forming at the middle vien of my leaves. I am using 1000w/hps, in soil, I am using a 10-52-10 bloom booster. Any help?? Rating: 5