I've had this diamond goby for about 5 weeks now. While in quarantine he ate frozen mysis fine from the bare bottom and seemed to get enough to eat. Now that he's in the main tank i've tried frozen mysis and sinking pellets and he tries to eat them but it comes back out his gills. He looks a bit skinnier than in quarantine. I'm worried. I treated him with Prazi during quarantine so I know he doesn't have parasites. Any ideas what is going on or what I can do to fix the problem? He will swim into the water column and eat the mysis but the exact same size piece he took in comes right back out his gills. I'm so confused and stressed. I don't want him to starve to death while eating.