These are not fish i would buy online. I'm 4 for 5 of success with them. The one bad one was thin to begin with and i gave it a shot. Target or spotted mandys are easier then green mandys to convert to frozen food. There more aggressive with eachother aswell. You want to buy an active round mandy. Not skinny with a sunken belly. Once home while floating the bag to temp acclimate i add a few brine shrimp frozen. In this enclosed and solitary environment all my mandys ate the shrimp. Imo its not so much they wont eat frozen food its that they have to A. Have time to get to/ eat it. B. Be given the chance to sample some frozen. Ie in the bag. Once brine is accepted frozen cyclopeese, mysis, prawn roe, even small pellets can be fed. With difficult fish live brine is often gobbled