clam orientation with respect to current flow

[ReefDream]

What the best way to position a clam with respect to modest current? I know one shouldn't position the clam such that the current makes the mantle blow upward, but besides that, do folks find that one orientation is better than another? If set parallel to the flow, should the big hole (inlet) face upstream or down?

 

[firechild]

Generally it doesn't matter too much how the clam is orientated, they will often turn a bit wherever you place them. If you place them parallel to flow, I would put the inhalent syphon facing upstream.

 

[miniv]

My clams (the ones not attached to rockwork) have all oriented themselves with the inhalant siphon facing into the current.