Can anyone help me with this problem?
They look like they are starving. What kind of soil are they in?
What are you watering with?
pH of water?
Agree with @Spiney_norman. Those questions he asked are essential in diagnosing the problem. Here is my go to for checking leaf symptoms. No help at the moment but useful further in growth.
What should I do?
They turn yellow when they are 2 weeks old, I use organic soil, sand, perlite, burnt husks,
We need to know exactly what brand and particular soil you have.
Maybe take a pic of the bag.
Are you feeding anything?
Do you have a pH meter? If not you need to get one. They are not too expensive but it is vital.
COPY/PASTE the below list into your forum post.
Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)
-What strain, Seed bank, or bag seed (photo or auto)
-Age of plant/what week of flower
-Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
-Vessels: Pots, Grow beds, Buckets, fabric pots
-PH and TDS of Water, Solution, runoff (if Applicable)
-PPM/TDS or EC of nutrient solution if applicable
-Method used to measure PH and TDS
-Indoor or Outdoor if indoor, size of grow space
-Light system LED, MH/HPS/CMH/Fluorescents, or other
-Actual wattage draw of lights
-Current Light Schedule
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; Yes, No, Size
-AC, Humidifier, De-humidifier,
-Co2; Yes, No
If growing Hydro some additional questions:
-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution
Always try to upload a clear picture in white light of any issues you may have to allow the community to assist you.
Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner