Tom,
High light is a must - so what type of lighting do you have, what depth is the clam at, and what color is it (as the brighter colors usually require higher light)?
Also, depending on the size of the clam, phytoplankton additions may be necessary (smaller clams must be fed, as they can't produce enough energy via photosynthesis, but this becomes less important as the clam grows larger) - so what size is your clam?
Kevin
[ February 28, 2002: Message edited by: Anemone ]</p>