Tiny white things growing on glass identification

Hello. I've had these thing growing on the inside of the tank for a while, they come off when cleaning the glass while i´m doing water changes but within a couple days they come back. They are stuck on the glass, they don´t crawl around link other posts i have found.
Here I was able to get a macro shot flipping my lens around, but its hard to get good focus. Any body know exactly what they are? I´m looking for the name of species, to learn about them. Fyi, thats a tiny tiny scratch in the glass in the second image.
Here are the links to the images in case they dont appear correctly:
https://imgur.com/3HmCQn2
https://imgur.com/8N9jZhy


Here I was able to get a macro shot flipping my lens around, but its hard to get good focus. Any body know exactly what they are? I´m looking for the name of species, to learn about them. Fyi, thats a tiny tiny scratch in the glass in the second image.
Here are the links to the images in case they dont appear correctly:
https://imgur.com/3HmCQn2
https://imgur.com/8N9jZhy

