Ramshorns, MTS, Amano shrimp, Cherry Shrimp.
Ramshorns only breed like crazy when you are not tring to get then to breed :icon_roll I have Blues in one tank Reds in another. The more I want them to bred seems the less they do.
Ramshorns eat algae, DEAD plant leaves, and uneaten fish food. They are not a problem with healthy live plants.
MTS - Do come out at night and do eat algae.
Tried Nerite snails, IMHO their algae eating isn't worth the mess they make with the eggs. I still have nerite snail eggs after 6mos.