Blanching vegetables is a common way to soften them up for algae eaters. Doing this to zuchinni is great food for siamese algae eaters. Cut the cucumber, or better zuchinni, in 3/8 inch circles and boil for 3 minutes. Rinse, dry, and wrap individually in aluminum foil and freeze. When you need to feed your fish just drop one in the tank.
In theory if you find a food that snails like, they will congregate on it when the lights are out. At which time you can snatch them away.