The tank is not large enough but this sort of fish tends to have an extremely poor survival rate in captivity. I think this one is marginally better (unlike the more commonly sold harlequin sweetlips) but there is no guarantee of long term success. If it does live, it gets large, poses a threat to many different types of inverts, and tends - as do all sweetlips- to lose their attractive coloration. Personally, I would trade it in for something more suitable, and more likely to do well in that size tank.