There are several options to control snails in a planted aquarium:
1. Manually remove the snails. This means physically removing them from the tank. This may be time consuming, but is the most effective way to reduce the snail population.
2. Introduce predators. This includes fish that feed on snails, such as loaches, puffers, and some species of shrimp.
3. Use chemical treatments. There are chemical treatments available that are specifically designed to kill snails, such as copper-based medications. Be sure to use these treatments with caution, as they can also harm other tank inhabitants.
4. Introduce natural snail predators. Assassin snails, as well as some species of shrimp and fish, feed on snails and can help reduce the population.
5. Reduce food sources. Snails feed on detritus, uneaten food, and algae. Keeping the tank clean, removing uneaten food, and using a phosphate remover can help reduce the availability of food sources.