Looks like (old) leaf tip irritation. When fans blow the leaves around, the leaves can rub against each other, which will irritate 'sores' in themselves and the other leaves. Not much can be done about it.
Can also happen if you 'crush' a portion of the leaf. Like picking-up the pot and trapping a piece of the leaf between your finger and the pot.

The lower leaf with brown edges is likely from hanging too close (touching) the medium.

Old leaves are old news, but your newer growth looks pretty good.
Rusty Trichome Reviewed by Rusty Trichome on . HOLES IN MY SEEDLINGS LEAFS MY GIRLS NEED HELP ASAP PLEASE Hey, thanks for reading/replying to my thread I got theses a few weeks ago,, and i been tending to them ever since i went and bought the cannabis bible and have done my fair share of reseach and what not. BUT i dont know it all and this is my 2nd attempt (first we going well until my mom found them about 7 or 8 years ago) There are the holes almost like tears on the leafs. At first only 1 had it, then now it 2 more, they are growing big and are a beautiful green color, but i am worried Rating: 5