How do I know if I am ready.

[eclipse29]

I think clams are beautiful creatures. how do I know when my tank is ready for a clam. it has been up and running for about 8-9 months.
I have 324W of T-5 lighting
params.
Amm. 0
Nitrite 0
Nitrate 0
Phos. 0
Ca. 350 (Its low and I am in the process of stabalizing it)
Alk. 9.5 DkH