Yellow leaves

[misu]

some body know what is the problem ? all my plant are yellow thanks a lot !

 

[Old Salt]

to the forum misu!

It looks like you have calcium and nitrogen deficiencies. We'll need to know more to determine how to fix this. Check out How to Ask for Grow Support

 

[misu]

thanks a lot for your reply , i was reading all a bout and i did everery thing but nothing help and now all my plant stalk is purple

 

[Vulx]

thanks a lot for your reply , i was reading all a bout and i did everery thing but nothing help and now all my plant stalk is purple

What Strain is it?
Is it Indica, Sativa or Hybrid? What percentages?
How Many Plants?
Is it in Vegetative or Flowering Stage?
If in Vegetative Stage... How Long?
If in Flowering Stage... How Long?
Indoor or Outdoor?
Soil or Hydro?
If Hydro, Reservoir size?
If Hydro, Reservoir Temperature?
If Hydro, what type of Medium?
If Hydro, what type of Setup?
If Soil... What is in your Mix?
If Soil... What Size Pot?
Size (Wattage) of Light? How Many?
Is it Air Cooled?
Temperature of Room/Cabinet?
RH of Room/Cabinet?
PH of Medium or Reservoir?
Any Pests?
How Often are you Watering?
Type and Strength of Fertilizers used?
Size or Square Footage of Room?

This is to what Salt was referring - that info is available in the link he posted. If you respond to all these questions in a list format (there's an example if you click that link) you'll be able to get better help.

It's difficult to be able to properly diagnose your issues with limited information.

Edit: Please also tell us what you have tried, if anything, already.