It's always interesting to me when I hear other hobbyists say that their apple snails aka mystery snails eat algae.... I've just had a totally different experience with them. I've had countless apple snails over the years and have never considered them an algae eater. Nerites are fantastic algae eaters, they are the only snail I've ever kept that eats only algae. They also will not reproduce in freshwater and come in many attractive colors and patterns. Ramshorn snails are personally my favorite algae eating snail, they also feed on plant detritus and leftover food, but they aren't for everyone. They will reproduce but if you don't overfeed that shouldn't be a problem.