I picked up, what I believe is Tridacna Maximus (please correct me if I'm wrong), which is about 3-4" in length. It looked very healthy in the LFS, open, not gaping, nice color. It's been in my tank a couple of days, and still hasn't opened like in the store. Before placing it in my tank, I did acclimate for temp and to my water parameters. It's on the bottom of a 24" deep 120 resting in a nice curved piece if rock to attach to. Lighting is 2 250HQI MH and 4 T5's. Tank is about 2 years old, water parameters are fine. Is there any thing I should be concerned about?