Snails can be invaluable to an aquarium ecosystem, eating algae and organic debris while cleaning the substrate. Unfortunately, some species reproduce rapidly and can quickly take over a tank - an unplanned snail outbreak is usually an indicator of less-than-ideal conditions, making its control even more challenging once established.
Freshwater aquarium snails tend to be scavengers that consume anything that comes within their range, from dead fish, extra food for other fish and plants, even algae. Most are compatible with most freshwater species and thrive under most standard parameters.
Bladder Snails (Achatinella gracilis) are among the most widely known aquarium snails, being smaller than most scavengers at about an inch and olive-green to speckled brown in color. You can usually find these snails at most pet stores and they are considered safe with most aquarium plants - making them a popular choice as they will clean out your tank's corners while turning over substrate regularly to mix in mulch for plant growth and prevent cyanobacteria build-up - as well as having low toxicity levels and being very hardy creatures!
Ramshorn Snails (Melanoides tuberculata) are another popular aquarium snail species. As with the Bladder Snail, these hermaphrodite snails reproduce at will and may become favorites of some aquarists due to their striking shell shapes and various color options; others, however, consider them nuisance species due to their appetite for soft algae or dead plant matter that they chow down on. In order to control their numbers effectively it's best to refrain from overfeeding them while scraping sides or vacuuming substrate as they will quickly devour any soft algae or dead plant matter they find available; keeping these numbers down means avoiding overfeeding them by cutting back or scraping sides and vacuuming substrate as much as possible as well as cleaning detritus away as possible from both sides or by vacuuming up all sides or vacuuming up detritus from vacuuming the substrate regularly!
