Possible bugs or...? Very urgent

This happened since I last checked on my plants at like midnight last night, and its on various spots on other leaves, curious as to what it could be. I fed them about 2 days ago and today I got these, I woudl assume some sort of deficiency but on the underside its like the leaf is eaten away from the stem, and all thats left is just the a translucent layer on top of the leaf. I checked under all the leafs but couldnt see anything, so I am very unsure what this could be, but saying it happened basically over night, worries me greatly. So what does this look like and how do I fix



Thanks!

if its mites its a pain to see if the infestation is small. its hard to really see your pics so im not gonna say yes or no on what it is so ill leave you with this an ounce of prevention is worth a pound of cure, its a good thing if you invest in neem oil or i use humbolt sticky foilar spray because its got soap in it which helps give the plant a bitter taste bug dont like an keep it clean.

Yeah hopefully its nothing too serious because I cant get out to the hydroponics store till wednesday