Help - Crocea clams not happy

[Ruth]

I don't know what is going on. I have 3 crocea clams, 2 squamosa's and a derasa clam. All 3 crocea clams have their mantles pulled in and are not extending. The other 3 clams appear to be fine. It started last night - or at least that is when I noticed it. I cannot see any predatory snails around their mantles. Water quality seems to be fine.
temp - 79
Ca. - 460
Alk/Dkh - 9.2
Mg. - 1350
Nitrates 10
Nitrites - 0
Ammonia - 0

My Nitrates always seem to run about 10-15ppm because of my fish load. I have had these clams for about a year.
I added a couple of acros and an acan last week.
The only thing that has changed in this tank in the past 8 months is that I was feeding reef roids for a couple of weeks but stopped last week when I noticed that my green carpet anemone was not doing well.

I was going to try a fresh water dip but am worried about stressing them some more. Any suggestions?

[shotzee]

What was the matter with the carpet? Could it be related to your clams conditions? If you think that it could be, you could try using carbon for a little while.

I would not do a FW dip with the clams if they already looked stressed, but just giive them a little while. It is a little wierd how it has only affected the crocea's, but I would guess its a water quality issue rather than a predator.

[Ruth]

Well wouldn't you just know that my canister filter would crap out right when I need it and when I went to replace the filter bag of carbon in my sump the bag broke. Anyway I have added a large new filter bag of fresh carbon (Black Diamond) and fished most of the loose carbon out of my sump. I'll see if this helps at all.

[Andy]

Hi Ruth

Are the clams on the sand bed or up on the rocks. What water depth and lighting? Do you have any fish that might be either nipping the clams or picking on any possible pyramiddal snails. I often see my yellow wrasses picking on the edges of the clam shells. This causes the mantles to retract for a period of time. Often times, clams will just expire for no apparent reason. They look great one day and are dead the next. Hope your's recover.

Andy

[geopod]

Ruth,

I have a clam and it didnt open for a few days. So I did some looking around the inside of it between the mantle and the shell and low and behold there was 2 little asternia star fish in there.2 minutes after i fished them out with a toothpick the clam opened back up.....
My 2 sense for ya


george

[Ruth]

All 3 are up on the rocks - approx. 12" below 400W MH lights. I have not moved them in probably 6 months, except for one guy that fell off his rock. The one that I noticed this on first seems to have become unattached to the rockwork which has me thinking that maybe something is picking at their feet. My other 3 clams are down in the sand and they seem to be doing just fine - fully extended and looking good. I have not seen any fish picking at them and I cannot see any pyramiddal (sp) snails on their shells. I don't know what else I could test for as far as water quality goes. I did a phosphate test and it is about .03 with a Salifert test kit.