What is your light source?
Hangs pretty steady at 64/65. In a pretty stable environment.
Done a bunch of research and I think I may be experiencing potassium deficiency. I have leaf necrosis and very short roots which are both symptoms.
Any thoughts on that?
Hard to tell with your pictures... they are very small and you can't see detail. Are you buffering with potassium bicarbonate? Could also be magnesium... spray the leaves with some Epsom salts dissolved in water.