Sometimes I have snails in my aquarium, and I have hard times getting rid of them.
I was wondering, do they pose any harm to the fish in my aquarium? I mainly remove them because they are ugly and they eat some of my plants (my expensive plants).
According to thinkfish.co.uk, snails are a potential disease vector. However, this is usually only an issue if the snails come from the wild, or from a tank that already has a disease infecting the residents.
So long as you are reasonably certain of the provenance of your snails, you should be safe. Keep in mind, though, that snail eggs can be easy to miss, so if you replace some of your expensive plants with free ones that you found in a pond or stream somewhere, you run the risk of introducing wild snails.