Pump recommendation

[apex82]

Eheim are the way to go if noise is any issue for you... I use the eheim compact and its great.

[sphelps]

Clams do not require high flow, they do better with low to moderate flow. A 30X turnover in a small cube tank will actually have negative effects on clams, too much flow and too much substrate movement will cause the clams to stress out. A pump rated at around 600GPH will be all you need providing over 10X actual turnover which is better for clams.