Hello, i have had a feather duster for about 3 weeks now. Just recently i have noticed that he is losing some of his feathers. He is not losing his whole crown or anthing just missing some feathers. It almost looks like something is chewing them off. Though i have yet to see anything go after him and all i have are 2 f. percs, 2 small green chromis and 1 royal gramma. I dont have any exact numbers for a water test because i ordered new test kits and they havent come yet. Though im pretty sure everything is normal because everything else is doing fine in my tank. I usually feed him phytoplankton or a mix of other finely chopped meaty goods. any suggestions?