I know I have loads of MTS, as I've added them myself on purpose, and know what they look like.... here's one of my big ones, about 25mm long But I recently added some live plants from the LFS, and since then I've seen a couple of different snails, that I dont know what they are. More to the point, I don't know if they're good or bad! They are more like a 'traditional' snail style, with a full body in contact with the surface, with a roundish shell on the middle of their back. here's a few pictures I took, it wouldn't come off the glass to get a good pic of it from the side. It also moves a LOT faster than an MTS, like a Ferrarri compared to MTS speed!! And I could definately see it eating the brown diatom algae off the glass. Oh yeah, its very tiny too, only about 4 or 5mm long. I reckon there's at least a couple of them there. Anyone know what this is? If it's good or bad? Should I keep it or kill them?