Please help with possible Iron diffency

[Greenleaf]

Hello all, this is my first coco grow, I'm growing 4 Blackberry autos, and 1 CheeseXXL auto. All the plants are doing well except for the Cheese, the top few and the new top leaves are all yellow. The plants are about 2 1\2 weeks old. Ive made sure my p.h. is at 6.0 to 5.8 I add 5ml. of calmag with each watering but I can't figure out what the problem is except for maybe an Iron def. If anyone can help I'd appreciate it.

[Greenleaf]

This is the Cheese with the yellowing leaves.

[Mr.furley]

Hi Greenleaf
First off a picture really helps, do you have one? Most new leaf is light green to start with but darking.
so with the calmag you will need to move your PH from time to time to inbwtween 6.0 and 6.5 so your plant can catch it.

[Greenleaf]

Thanks Mr. Furley I'll keep that in mind.

[Canuck147]

Doesn't look yellow to me - different strains grow different ways. Just a different color green than your other plants that I can't see.

[Greenleaf]

I know it didn't look that yellow in the pic. but it is. I think I know what may have happened, I over watered for a time and may have caused a Zinc def. Because they were more yellow before and after reading the plant problem section here on the site that's what I came up with. Than you for your replies though.

[Mr.furley]

Yeah I would do anything.

[Toker1]

You should not shoot for a specific PH every time you water or feed. Instead, try to get a nice spread between the ranges of 5.5 and 6.5. So the plant has the opportunity to absorb a greater amount of nutrients.