I would have kept the snails just I find the regular pond ones a bit ugly and I don't care about algae that much because of saes and guppies. Oh well, I'll try to pick them off by hand next time instead of using saltwater. Totally didn't cross my mind that this would happen after hearing that hornwort is an uncontrollable invasive weed that grows 10 feet in a week. Hahahah.The salt dip dehydrated it,also hornwort does better with pond snails,as snails turn organic materials into chemicals plants use and help keep algae off the plants.
As an update the hornwort is coming back! In the last week it has put about an inch or so on, even in the low light guppy tank. I guess the stems were still alive after all! Hopefully my fry will really like this plant.