aquawolf - You are absolutely correct, and in my haste I omitted care information and suggestions. It is true that Flame scallops usually fall under the moderate-to-difficult category, and the main reason for this is the fact that their sole source of nutrition is through filter feeding.
There is a tricky curve and relationship between the health of a reef-type aquarium and the health of these and other pure filter-feeders in that the cleaner your water is (in terms of particulate organic matter, POM) the worse it is for a flame scallop in terms of food availability. However, when you slide to the other side of the spectrum and have "dirtier" water (again, relating to POM) the worse the parameters of the water often are for the health of the scallop and other organisms; especially invertebrates. Therefore it is very tricky to establish and maintain a proper balance of "food" and "water quality" in an aquarium.
One of the main ways to ameliorate this is to target or spot feed the organism (or feed the system if you have successfully been doing so already, though target feeding is always recommended and encouraged). Rotifers, phytoplankton, and zooplankton, as well as products that mimic natural marine snow are all ways to supplement the filter feeders' diets. These are the exact methods used by many reefers of varying merit to successfully increase the health of the corals. So, if one is going to those lengths anyway, then he or she would easily be able to add the scallop to his or her feeding routine, and hopefully would be successful in keeping it.
Another thing to consider about these organisms is that they often hide underneath rocks, and can sometimes only be seen from certain angles or only the tentacles are exposed. Therefore these animals should only be attempted by those who either know from experience they can keep them alive, or someone who has read or knows this information previously, already has a feeding routine or is willing to start one, and is willing to try to keep one.
Here are some links to further information:
Central Pets &
Advanced Aquarist Magazine
I apologize for this slip up, and next time I will remember to have taken the extra time to introduce appropriate information about any animals or products we may offer to offer in the future.
Cheers,
Graham
Coral Morphologic