Some fish it takes much longer to get acclimated. Has he found a place to hang out by himself? As long as he is eating off rocks it should be ok. You do have algae in your tank correct? If so, it should not be an issue. Just leave the seaweed over night and just let it go. Does he looked starved at all, or is his stomach looking good. Send us a picture if you can!
3 Gallon Betta, 14 Gallon BioCube Planted, 29 Gallon Community, 29 Gallon Parrot Cichlid/Pleco
46 Bowfront Reef Tank, 3 Cats, 1 Choc. Lab