Actually, the gigas can deal with the VHO nicely even if it is that close to the light. When they are so young, they are attached to rock still, so it is fine for them to be on rock.
I said he doesn't NEED to keep the gigas so high, not that the clam is unable to deal with the light. :wink: I have my gigas under 250W HQI on the sand bed. The point is that there is no reason to have the gigas in an awkward position so high in the tank unless you think it needs to be there. The tank has enough light where the gigas can deal with being on the sand bed just fine.