kryptonite-
I use VHO's (1 aquasun, 2 actinics, 1 NO actinic). Total watts is 245. I have never had a problem keeping corals (xenia, pineapple coral, hammer, montipora). All of them have multiplied. I have to clean the front glass every two to three days due to algae growth. Since everything seems to be thriving I decided on the Squamosa.
The tank is a 25 gallon. The clam is 14 inches from the light. Light Duration is 12 hours.
Your clam might still be acclimating. I would give it a couple of weeks before changing anything.
I honestly do not know if you have enough light or not! I do know that Squamosa's are natural found at depths of 32 to 48 feet. If everything is growing in your tank I would think that your fine.
I based my decision off of known facts. The tank has been doing great for 8 months. I have watched my corals grow. I have to clean the front of my glass every two days due to light. These were my deciding factors.
I would give the clam a few weeks. Let it acclimate to the new light. If everything is growing in your tank, I would not worry. Feed it DT's every other day (I was worried about an algae bloom and it never happened). If you feel that your lacking in light, maybe increase your light duration.
I have never seen bleaching. If in doubt, you should post a pic. These guys are pretty smart about clams. They will be able to tell you if it is bleaching.
Keep me up to date...
Heath