Most reefers with at least a decent amount of experience already know the importance of having some knowledge regarding what they're about to add to their tank before making a purchase but for those who are new or just haven't been in the hobby for long enough may not realize the point of doing research on what you want to keep. It's a daily occurrence to come across threads asking why X invert or fish died when just a bit of research or asking questions would have given off a number of red flags. For instance, the first addition to your tank probably shouldn't be a difficult species of anemone (or almost any anemone for that matter). There are reasons for this and it isn't because people are just jealous of how beautiful your anemone is in comparison to theirs. An even better example is starfish. There are a few that will do fine in captivity without tediously caring for them and having the willingness to dedicate extra time only to them. However, these usually aren't the species people tend to want to stock. Instead they opt for various Linckia species (in particular blue Linckias), Fromia species, and others simply because they like how they look and impulse buy. This has escalated to the point that Linckias laegivata (Blue Linckias) make up approximately 3% of inverts harvested from the wild according to some sources. (I don't know the accuracy of this number but I do know that a ridiculous number are imported and die rather quickly. It's my belief that even though some reefkeepers who have even been in the hobby for some time believe that simply because their system is large, because they keep a "dirty" tank, or due to the fact their tank is stable they won't have the same problems 99% of people do. The associated issues are far more complicated than any of that which proper research (not only asking the opinion of someone who's been successful to reinforce your belief that youll be able to keep them long term, but doing other research as well) will tell you. There are many fish that have similar issues being kept in captivity as well. Please just do your due diligence for yourself, your bank account, and of course for the sake of the fish/invert.