Turn off filter snail removal?

Hello Everyone, I have a 30 gallon and a 20 gallon tank. I have snails in both. The snails in the 30 gallon were easy to remove. I just turned the lights off and they all gatther to the javamoss like moths to a light. That doesnt work for the ones in the 20 gal. Tey are eating all my plants and I have tried so much. They are small and dark brown shells. My question is, would turning off my filter cause them to aculate at the top? That would make things so much easier. any feedback is greatly appreciated