Clams under lower light systems?

[smokinreefer]

Paul's Aquarium in Surrey is selling clams out of a 10 gallon nano with about 26W of what looks like 3000K PC over them

if only it were that easy....
unfortunately you cant guage an animals requirments by what you saw at the LFS, simply because, the LFS expects a high turnover, so they don't always keep animals in their required environment.
i'll bet you a clam, that if you bought one of their clams and kept it under a 26W light, it'll die on ya in no time!

that being said, with enough VHO, you can probably keep any clam. and a derasa or squamosa would be a good place to start.

just for an idea on requirements, a guy on RC has maxs and crocs on his sandbed of a 24" deep tank (120G tank), lit by 2 x 150W 6500k MH and VHOs.

so. i'd say you shouldnt have a problem.