Is this potassium def?

Is this potassium def? I have looked at a lot of pictures and haven't really found anything that looks similar to this... It might be potassium if I had to guess...

Any ideas?

I am using 4ml humboldt oneness and 2ml calmag and 4ml hygrozyme (all measurements are per gallon)... Growing in hydroton with an ebb and gro bucket system...

Thanks,
MonsterRobot

look here https://www.rollitup.org/marijuana-plant-problems/157345-have-plant-problem-check-here.html but looks like nute burn to me.

I have checked that out before and thanks... but the reason that I don't think it is nute burn is because I have ran the same strains at the same nute ratios and everything has been fine... Maybe the cuts were taken from different mothers since I got them from a dispensary and I am not really sure... I did recently change my res but I used the same ratios with the ferts and I haven't had problems before and I haven't changed anything...