I think my Maxima clams are dying

I recently purchased 2 maxima clams. After acclimating, I placed them both on the substrate (Aragonite Live--fine).

My tank is 29" high, and is lit by 3 Ecotech Radion XR15's that come on around 1:00 PM and shut-off around 11:30 PM. They start off at blue and gradually work there way up to full blast in all colors around 2:00 until 10:00 when they start getting darker/bluer until they shut-off altogether around 11:00 PM.

As they are on the substrate, there is what understand to be good flow for them.

My concern is that they are not opening much -- they're always not even 1/2 opened. I believe they are stressed, but I don't know why.

Do you have any suggestions? Should i cut back on the light? Move them higher than on the substrate?

Thank you.

How did you acclimate the clams? How long have the clams been in your tank? What livestock do you have in your tank and have you noticed anything bothering them? What are your water parameters?

You can keep them down low but I would put them on a flat rock, a pvc coupling, or something so it can be off of the sand a little. I don't know what kind of lighting the clams were kept under where you bought them but it is always a good idea to acclimate them to your lighting. Especially, since you have pretty intense LED's.

See if they respond to light, put your hand between the light and clam.
If it doesn't respond, check for pyramid snails on or near the foot.
To be honest, they don't look good. If the mantle falls anymore, they are done.

Is it possible that those lights on full blast are too much? I'm not familiar with it off hand, but they are high intensity. From what I've seen others run theirs at a fraction of full intensity.

Any update on the clams? Maybe I'm reading it wrong, but are you running the lights at 100% from 2 to 10? If so, than you might want to slowly ramp them up to 100% and only have at 100% for a few hours, then slowly ramp back down. Sunrise/sunset effect.