Experianced help needed

first pic grapefruit from next gen. a little light green for an indica, tips dieing and curling, tip edges are curling slightly. supposedly a nute hungry strain.
next pic. bubbleicious nirvana, edges are curling and dieing.
ppm 1.3 got a little worse when ppm was at .8 ph goes between 5.6/6.1 try to keep it at 5.8.
using advanced gmb/ big bud.
i believe it is a mag deff. but it could be nute burn.. any help would be appreciated...

these plants have been in flower for 8 days these spots have occured between 3-6 days..

Calcium starts at the edges with red-ish dots. Magnesium def is interveinal. You've got salt issues or low humidity.

bumpity bump
help me out now cmon

bump it up