10k IMO will work just as well for macros and clams as 6500k of the same bulb type/wattage, and is a little more aesthetically pleasing. I could post a link to another site where clams and macros are featured in the same tank just not sure if it may be agianst the UA. BTW in nature clams and plants are found in similar if not the same environments. So it would be natural to display them together.
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~David~
300+gal multitank, seagrass, mixed reef, clown anemone, refugium, and sump. | 
