You can toss a piece of zucchini in the tank at night and pull it out with snails on it in the morning, a lot of people don't like this one but I'll say it anyways, you can buy some assassin snails to control the population, I have assassins but I bought them as a pet before I had snails because I enjoy their colors, of course also like mumma said less feeding and snails are good for your tank in my opinion. I'm not 100% possitive that 2nd pic is a MTS, may be or it may be a pond/bladder snail. Either way pond or MTS or ramshorn they are a good clean up crew for your tanks if ya ask me.