Easily 500lbs. People get hurt by trying to lift them!
Smaller clams needs substitute feeding, be sure to keep that in mind.
ya calms need phytoplankton feeding up to about 3-4 inches long. another must is metal halides or MANY T-5 tubes, they come from shallow waters, thus they recieve much light...to the level of which we cant even really copy. and really unless u have a 500 gallon aquarium you want to stay away form
T. gigas clams.
T. maxima,
T. corcea,
T. dersasa,
T. squamosa and
Hippopus hippopus clams are much better suited for aquaria.
corceas getting about 6 inches max and the others 12-20 inches. they also need high calcium levels kept constantly above 400.
at the apparent size...guessing that flam hawk is about 2-4 inches ull need to feed that calm in addition to strong light. Dt's live phytoplankton is the best route to take for food.