Betta Fish: Tiny white creatures crawling in my tank?

I have a fish tank with a Betta, Otocinclus, and a Mystery Snail. I’ve had this tank for over a month now and we did a full tank change since it was getting too dirty and now there are all of these white things moving along the tank and everywhere in the water. There was a small worm too which my Betta fish ate, I know they’re beneficial for the tank but there is way too many. What do I do? How can I get rid of a lot of them without killing my snail?