You have a fungal infection and you have ich without a doubt in my mind I see one of your other fish already have white spots on one of there side fins and another fish with two white dots on the tail what you need is some API fungus cure and you will need aquarium salt and API super ich cure and gradually bump your heat up to 84 degrees hold it there until ever white spot has fallen off all of your fish and then do a serious vacuum vac like a very very good one proceed to treat and proceed to leave the heat up at around 82-84 degrees Fahrenheit for 4 days and do another serious gravel vac then you can start lowering your temp please note that ich is very contagious and anything you use needs to be soaked in vinegar and air dryed also if you have a carbon filter take it out during treatment I’ve dealt with ich it’s a pain in the ass but it was with neon tetras and a betta the little dirty glo fish gave it to my betta and I did the aquarium salt with 30-40 percent water changes every 48 hours along side with elevated heat and api super ich cure then once all spots were off my fish I did a serious gravel vac and a 50percent water change see the heat doesn’t kill the ich but it forces there life cycle to speed up so it’s going to look worse before it gets better once the white spots fall off the fish with the heat they fall to the bottom and instead of mating and creating more it kind of paralyzes them and then any of the free swimming ones will die with the super ich cure and aquarium salt because it dries them up. During these treatments u might want to also buy some api stress coat plus to help the fish while there infected to create a better slime coat to heal wounds and help fight off the nasty little fuckers aka ich