My tank has been overrun by little snails that came in on plants the population kept getting bigger and bigger, so it was time to take action. It’s a 20 gallon long tank and so I added for assassin snails to the tank. I took out my nerite snails so they wouldn’t be eaten. It may be a long process, and I probably should’ve put in several more of these assassin snails to speed it up but at least I can see that they are working on the snails. My understanding is that there will be one winner, one Assassin left after everything has been taken care of.