I did ask Charles Delbeek about that too. He mentioned that supplemental wouldn't do harm to your tank, but it may have reprecussions on your overall system. A clam probably wouldn't efficiently utilize the feeding unless it is constantly in the system. They are not like fish, where they eat whats being fed to them. It most cases they probably won't eat most of the supplemental feeding. If the clam is not eating/absorbing it, then it just goes into your system a waste. I've seen alot people with massive algae blooms caused from too much supplemental feeding. Once the feedings were stopped, the algae blooms subsided.
In any case, I think it's better to just provide the proper amount of light, calcium levels, water quality, and mimimize a potential sources of stress. :rollface: