main leaves yellowing and dying

is it common for the main water leafs to turn brown and start dying off whenyou get several weeks into budding? due to the lack of N. Its happen to about 4 out of 6 of my plants. the buds look fine but even some of the little leafs with the trics on them are turning brownish. but again the buds look absolutly fine. ive seen lots of pics of peoples plants and ALOT of the pics show their leafs dying also, except for the buds. bbut some pics show perfectly healty leafs all over the plant. Its nothign im really too worried about, until i see the buds taking a turn for the worse. than ill start to worry. i use FF nutes. right now im using 4 tb of Bigbloom and 4 tesp of TigerBloom per gallon.

Not familar with your nutes but with my nutes while in flowering I still run about an 1/8 of grow with the bloom juice to prevent N defiencencies.
Stay on top of PH first. Most cases of PH being to high/low is mistaking by difenciencies.

Best of Luck,
Blatrix