ok first off im no genius when it comes to clams. i had my maxima clam on the sandbed for a day without a rock. then i moved it to a rock and let it set for a few day (2) i tried to move it but it to see if it was attached and it just fell off. so on sunday i put it in a tupperware container on a rock and put screen over it. today it is still not attached. i now have it as high up as possible on a rock. it is probobly a foot from the light now in stead on two. it hasnt opened up yet but thats prob because it took me a while before i could get it to balance right.