Nitrogen or Magnesium deficiancy?

Over the past week i have noticed lower fan leaves turning yellow on my three plants. The symptoms have led me to believe it's either a nitrogen or magnesium deficiancy but I can't distinguish. The breed is Serious Seed's AK-47. From the research i have done it should finish somewhere between 9 and 10 weeks. I vegged them from seed for two months. They are four weeks along in bloom, growing in 3 gal. soil pot's under a 600w air cooled Hps. I'm feeding them GH flora nutes, gradually building up to full strength. I feed every third day and use straight spring water, no nutes every third feeding. The last week and a half i have noticed slowed bud growth, yellowing lower leaves and a lighter green overall appearance. Let me know what you think and ask away if you have any further questions. here are some pics.

Here are some better pics of one of them.

I may add that I'm feeding them GH nutes and may have switched over to the "aggressive bloom" stage too early. The "aggressive bloom"(0ml flora gro, 5ml flora micro, 10ml florabloom) cuts off the flora gro completely and that may have been what caused a nitrogen deficiancy. I think the plant is still in the stage were aggressive veg growth going on, early in the flowering period. So it was not getting the required nitrogen. I think I'll switch back to the "Bloom" cycle nute ratio(2.5ml floragro, 5ml floramicro, 7.5ml florabloom) for a bit and switch to "Aggressive bloom" in another week or two. Let me know what you think? I still havn't ruled out magnesium defiency completely because i don't see it listed in any of the nute bottles.

I added more nitrogen last feeding. I hope this works. Does anyone have an opinion?

Freda Felcher said:

I may add that I'm feeding them GH nutes and may have switched over to the "aggressive bloom" stage too early. The "aggressive bloom"(0ml flora gro, 5ml flora micro, 10ml florabloom) cuts off the flora gro completely and that may have been what caused a nitrogen deficiancy. I think the plant is still in the stage were aggressive veg growth going on, early in the flowering period. So it was not getting the required nitrogen. I think I'll switch back to the "Bloom" cycle nute ratio(2.5ml floragro, 5ml floramicro, 7.5ml florabloom) for a bit and switch to "Aggressive bloom" in another week or two. Let me know what you think? I still havn't ruled out magnesium defiency completely because i don't see it listed in any of the nute bottles.

Click to expand...

I would just stay with the reg bloom schedule all way until they finish. And what is your soil ph and water ph? One of the first pics kinda showed signs of a possible ph issue.

im haveing the same problem dont know what to do

Looks like N def to me
just keep using ur micro and bloom and it should pull out of it
u should be able to use the micro and bloom thru the whole grow
goodluck

Looks pretty normal for the 4th week of flowering to me. A lot of the leaves start to die, it's expected. I would just stick with your routine and focus on the buds.

4th week of flower..

All you need to do is up your feed a little . Plant is fine .

Nice Plant

V