Noticed this today. Have not done anything different in week besides trimming some leaves
@420j0hn,I’m just getting Back into it (Growing) and Smoking Had Legal Issue’s Some off these People Might offer you advice,As My Note Book is still buried
@blackthumbbetty @Budbrother, @SmoknGranny @dbrn32, @raustin @merlin44 @MattyBear @dbrn32 @Josh1126
Untill Someone can Answer you,Open this Chart
Just a quick look seems like Calcium. Need some more info, though.
Agree with @blackthumbbetty. Picture in natural light is helpful, but it looks like a calcium deficiency to me.
This info helps us too:
Strain?
Photo or Auto?
Soil in pots?
System type?
PH of runoff or solution in reservoir?
What is strength of nutrient mix?
Indoor/Outdoor?
Light system, size?
Temps;
Humidity;
Ventilation system;
AC, Humidifier, De-humidifier?
Thing’s Are Slowly Coming Back
Thanks for the Quick Answer’s
I’m in agreement with @blackthumbbetty as well, but never hurts to fill out the support ticket to make sure 
With only the single picture it is a bit hard to say, but this looks like a fungus issue. Cut off the dead leaves and make sure airflow is good if indoors. If you start seeing more you might need to treat for it before it advances too much.