new clam?

[Perureef]

So today i bought a clam out of impulse. I know it shouldnt be done but it happened. It is about 2 inches long. The man who sold it to me said that it was Tridacna maxima, but it isnt blue, its rather like a creamy color, with spots at the ends of the mantle. He told me that it does not like sand, that it attaches to rock, so i place it on top of a small flat piece of live rock so that i can easily move the clam once it is attached to said rock. the clam has rather coarse "scales" on its side that stick out somewhat noticably. if the clam were to close up completely, the shell would make a perfect seal. Sorry i dont have a digital camera on me. I have placed it in my 72 gal. oceanic aquarium lit by 4 * 54 W t5's which are hung 3 1/2 inches above the surface. Currently the clam is 14 inches from the surface, but i can move it to some rock work that is 5 inches from the surface if necessary, although the ideal spot i would like to place it is roughly 7inches from the surface. Is this enough light? I would love to place it on the sand bed, which is 18 1/2 inches from the surface, but i suspect that the T5's arent enough light for any species of clam. does this sound like a maxima? Is this enough light for a maxima? Is it enough light for any type of Tridacnid clam? Sorry for the long post, but i would appreciate any help.

nitrite: 0
nitrate: 0
ph: 8.1
salinity 1.025
alkalinity 240 ppm
calcium: 400 ppm
light: 4 * 54W T5's, sunlight supply, on for 12 hrs a day
phosphate: <0.02 mg/L

The system is running for 1 year, 8 months

 

[mbbuna]

keep the clam where it is for a week or 2 and see how it respondes.i wouldn't put it on the sand. it sounds like a maxima but its hard to say with out a pic

 

[Don Berry]

Unfortunately you choose the type of Clam that needs the most light to live. I would put it as close to the light as possible, but it is going to be hard to keep a Maxima that small alive in your tank.

 

[Perureef]

ok thank you for your replies. so if the clam is in fact a maxima then it will likely not survive? how far can i keep it from the T5's and still expect it to grow? how do i tell if the clam is not getting enough light? what species can i keep under my setup, and at what point in my aquarium? thanks all for the info.