I have a diamond watchman sand sifter goby, about 4in. He plows the sand all day long, keeps the sand white all the time. Only bad part about sand sifter gobies is they deplete the sand bed of pods. If not keeping a mandarin, or other pod eating fish, I recommend this one. Yellow sleeper gobies will sift the sand but they tend to sift then swim up and release the sand...leaving your corals sandy. My two cents...