I’m not really familiar with caring for sand substrates, I know a lot of people with sand just kinda hover over the top of the sand to pick up waste. Since I’ve never had sand I’m not the best person to advise you, but I would suggest keeping an eye on it. Those worms are a sign of some kind of organic build up in the tank.
When I developed a lot of those those it wasn’t long before I started losing shrimp. I blamed it on everything else at first, but at the end of the day when I bit the bullet and cleaned the gravel I may have lost a few babies but the tank was way cleaner and the rest of the shrimp way healthier for it.
Is this in the tank where you have the angel with white spots that you’re trying to figure out how to treat? Because if so the snails may not like the salt.