My Nerite snails eat my bba, but do not eliminate it, unless that is all there is to eat algae-wise. A close observation of phosphates help, too. Sometimes the phosphates get a little high with new planted tank substrate. Raising the lights above the tank can sometimes help. In my anubias/ fern tank I placed pink colored plastic x stitch sheets over the tank and the bba was reduced, mostly because it reduced the other algae and the nerites then decided to eat it.