Clam looking bad

[AquaristicA]

I have problems with my clam retracting each day, and it has gotten worse and worse. Have no idea what it can be, Here are the water params:

Alk - 9

Mg - 1500

Ca- 440

Nitrate - 2

phosfates - 0.01

For lighting i run 2x 150w and 4x 39. I havent changed the bulbs on the T5 in 7-8 months, could that be a problem?

For fish i have:

1 yellow surgeon

1 firefish

4 chromises

1 sixline wrasse

I have done waterchanges and run carbon, but hasn't got any better. The clam has been in my tank for 2 months and looked very healthy the first 6 weeks.

Here's a pic

http://img260.imageshack.us/my.php?image=92011395zd7.jpg

 

[skinz78]

what is your ph?
What is your salinity
What is your temp
Nitrates should be zero
What unit of measurement are you useing for alk meq-l or dkh?
mg seems a little high

I think your yellow sturgeon and sixline may possibly be culprits too

 

[AquaristicA]

ph is 8.2

salinity1.026

temp 78

I am using Elos measuring kits

I thought nitrates was nutrition to the clam, that's what I've read...

 

[skinz78]

Hmm, well its hard for me to tell, how long have you had it?
are you useing any phosphate remover?

 

[AquaristicA]

Its been in my tank two months, dont use any phosphate remover

 

[a4twenty]

are there more corals close to the clam? the coral behind the clam, is it a brain / moon ....... and have you looked for sweeper tentacles that could be stinging the clam at night? he seems more retracted the closer he is to the coral.

have you inspected for pyramid snails? take a look a few hours after lights out for little white snails up on the shell or under the mantle. also look for any worms or anything else that don't belong on the clam.

how are you maintaining your Ca and Alk? ( what are you using and how )

i also agree that the yellow tang could be contributing to the problem. you need to stay well back from the tank ( make him think your not watching ) and see how he behaves.

 

[AquaristicA]

Ok, i'll have an eye on the tang. I maintain Ca an Alk with Balling+, dosing with Aquatronica's dosing pumps 60ml a day.
kept the tank stable from day one.

However, the brain coral cannot be the problem because the clam got worse in antoher place in the tank.