I'm 55 days into growing Big Buddha Auto from seed...

The first 3 pictures are from one plant and the last 2 pictures are from the second plant. The second plant is the one i'm worried about the most, and it's only the top leaves that are this damaged. I can't figure out whats happening to them since my other 2 plants are doing fine and the second plant is the shortest and farthest from the light so I don't think it's heat damage. They are in 3 gallon pots with drain holes.
I suspect root damage on the first plant because the soil tends to stay wet longer than the others. The leaf damage is not nearly as bad as the second plant though......I'm getting frustrated trying to figure out whats wrong with them....can anyone help me? I'm harvesting next week so it's to late for significant recovery but I'd like to prevent this in my future grows.

I dont think its ready for harvest at all. I had a problem simular, i just let the plant grow until it died completely. The next thing thats going to happen is that its going to dry out really bad along the stem and die >_>

I have some pics of mine when it did that, but ive uploaded like 400 pics and itd take me forever to find them x3

Those plants are starving to death. What are you feeding them? what are the temps in there?

look like phosphrous deficency, any one else?

hungry hungry plant, needs good food asap

The temp is at 80F and the light is more than a foot away from them. I was giving them half strength Bloom but cut back to quarter strength when I started seeing the leaf damage, I suspected Nute Burn. I'm also giving them some Cal-max and Carbo-load.

Damm mate.. that's one of the worst P def I've seen around here

How does a guy fix/prevent phosphorus deficiency? I really hate seeing my plants like this.

do you give them flower nutes?

i always use potting mix as it has nutrients in the soil and slow release nutrient grandules,
too late to fix now just look for the signs of it happening in the future or get better grade soil?
you only get out what you put in, ive learnt as well as everyone else, might also pay to watch the ph from the runoff as it may cause a lockout to stop nutrient absorbtion

Yea man some pre mixed bone meal could work for your soil.

Ya I gave them flower nutes, but i was only giving them half strength and went down to quarter strength when they looked nute burned.

The soil i'm using is very good soil and made to grow marijuana, but i'll check the ph next watering and see what it's like.