My experience in saltwater fishes is not much (newbie here) but with freshwater fishes, i found its better to add the more peaceful or smaller sized fishes first. But even then it also depends on the individual fish's personality. I have had some of my smaller fishes chase those bigger ones but most of the time every1 gets along fine.. But generally adding smaller and more peaceful fish first is usually advised and also knowing wad we want in our tanks from day 1 would help a lot in stocking up correctly (we all knw thats nvr the case though.. lol). Sent from Singapore Reef Club mobile app