Is it normal for Amanos to kind of hunch up and scrape themselves with their legs occasionally or even frequently? They appear to be scratching or cleaning themselves. my concern would be that something in my water is irritating them.
Otherwise they are active, growing, eating TONS of algae, and molting regularly. My water has 0 Ammonia and Nitrite, and 5ppm Nitrate.
Don't worry...my does the same...like Antionette have stated, it is their kind of behavior......As long as it is not turning whitish or just laying down on its side or not feeding...then something is wrong....