@Randy_Marsh with all respect. You have been on this forum enough to know we should see pictures of the whole plant and a support ticket.
You used to provide feedback to the new posters.
more cal nag next feeding maybe - I don’t have the ticket info - if you could provide me with the info please.
Can I get the support ticket please ?
Not the latest version I have seen going around.
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
- Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
- Vessels: Pots, Grow beds, Buckets, Troths
- PH of Water, Solution, runoff (if Applicable)
- PPM/TDS or EC of nutrient solution if applicable
- Indoor or Outdoor
- Light system
- Temps; Day, Night
- Humidity; Day, Night
- Ventilation system; Yes, No, Size
- AC, Humidifier, De-humidifier,
- Co2; Yes, No
Always try to upload a clear picture 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 
Thanks!
Please be as complete as possible. If soil please tell us WHAT soil. WHAT light etc. It’s all important.
Thank you 
PH of soil could be locking out Phosphorus or there’s not enough P
Could also be a touch of Ca In addition to P
Is it affecting more than that one leaf? Is it a lower older leaf?
P is mobile and if needed will reallocate from older leaves to newer growth so…P and or PH maybe
Hope this helps