Keeping clams?

[Chibils]

I have tried twice with clams now. My first attempt was more successful than my last - though the clam was farther away from the light than he should have been and disappeared one morning (shell was upside down, pried open). He showed his mantle, but his shell never opened. My next attempt went worse. This time, he was close to the light (4" from water surface with lights 6" or so off the water) but still would not open. He also showed his mantle, but only over the lips of his shell. I inspected him carefully for any pests (pyramid snails, etc.), and he looked clean. After the third or fourth day, he didn't open at all. His shell is now empty (I assume).

 

[t11t5]

What lighting do you use?

 

[mbbuna]

can you list lighting, filtration, results from every test kit you have,list all fish,shrimp and crabs

 

[Chibils]

Lighting: 2x 175w halide.
Filtration: Octo NW150, 75# lr, Chaetomorpha.
Ammonia: 0
Nitrite: 0
Nitrate: 0
Calcium: 420

Fish (at time of first clam's death):
2x Firefish
1x Court Jester Goby (Amblygobidon rainfordi)
(at time of second clam's death) 1x Blackspot Angel (Genicanthus melanospilops)

Inverts:
2x Brittle Star
A lot of hermits.
Astrea, mexican turbo, trochus, nassarius snails.

 

[mbbuna]

how about Sg, Alk and Mg?

 

[Chibils]

SG: 1.026
Alk and Mg I'll have to test for.

 

[ludiNano]

I thought when a clam died it stayed wide open. Isnt closing a reaction indicating life.