Posted 1 Year, 6 Months ago Scronty Gold Boarder Posts: 175   Like NetMax said, that's what they do. Now, if you have other species doing the same thing, zipping back and forth, up & down cornors, and repeatedly bumping glass, you may have high levels of nitrAte. ..........Frank The administrator has disabled public write access. Posted 1 Year, 6 Months ago Scronty Gold Boarder Posts: 175   It's a pretty mellow tank. Tetras, pleco, a raphael cat that hides all the time, a couple of corys. The pictus is a hoot, zoom, zoom. And a real vacuum cleaner at feeding time The administrator has disabled public write access.