Horn snail, also known as the horned nerite snail, is a popular freshwater aquarium snail that originates from Southeast Asia. It has a unique and distinctive pattern of horns on its shell and can grow up to 1 inch in length. 

The ideal pH level for a horn snail is between 7.0 to 8.0, and the water temperature should be maintained between 70 to 80 degrees Fahrenheit. They prefer slightly alkaline water conditions and require a well-established aquarium with stable water parameters. 

In terms of care, horn snails are relatively low-maintenance and can help keep the aquarium clean by feeding on algae and other debris. They can be kept in small groups, but it's important to ensure that the aquarium has enough space and hiding spots for each snail. They do not require any specific diet and can feed on algae, leftover fish food, and vegetable matter. Regular water changes and maintenance are also essential to keep the aquarium healthy and reduce stress levels for the snails.