There really aren't any fish that I'm aware of that would be considered bottom feeders that also eat algae. Most bottom feeders are scavengers like corys and ghost shrimp while algae eaters will be in all levels of the tank, where ever algae is present. My amano shrimp do spend a lot of time on the bottom so I guess they would be the closest to what you need. Siamese algae eaters might fit that catagory too but I've never seen mine spending a lot of time grazing the bottom. Neither of those will eat plants.