While they aren't beginner organisms, success (and reproduction in one anecdotal case) have been documented in systems that dose phyto regularly in their tanks.
If you are interested, there are many commercial algae blends that are quite feasible for dosing, even in larger tanks. Also, though it may seem that you are feeding more material (and causing pollution), the overall mass of the algae is not a problem, and the commercial blends remove the growth medium prior to packaging. This doesn't mean the load isn't there, and a skimmer will help in these cases.
Also, be aware that flame scallops are very likely to move, like anemones, until finding an ideal location.
They are filter feeding critters, so food availibility is key, but it can be done.
For further reading, I would suggest you look in ReefCentral's Nonphotosynthetic forums found here:
http://reefcentral.com/forums/forumdisplay.php?s=&forumid=555
Though it's for corals, the feeding techniques may be applicable to the scallop.
Enjoy!