Clam death

[bromion]

I just lost the first T. crocea clam I tried to keep in my system, and maybe some of you can help me diagnose the cause. It had been in the display tank for about a month and a half, and until Saturday it was looking good (as in, I hadn't noticed any signs of trouble, though they may have been there). Saturday I noticed the mantle was not extending, and worse, the clam was not closing when my hogfish swam nearby, as it usually would. In fact, the hogfish poked its head into the clam!

Saturday night I did a 5-gallon water change (~65 gal tank including sump) and tested the water. Undetected ammonia and nitrite, 10ppm nitrate, 0.03mg/L phosphate, 380 mg/L calcium, 8.1 pH, 1.022 sal, 5.8dKH alk. Alk was clearly low, so I raised it a bit with baking soda to 6.2 dKH.

This morning, clam was closed. I left for the day, came back around midnight, and the clam was being eaten by a hermit crab. Most of its flesh was gone. I inspected the shell for parasites and found none. I also never saw worms bothering the clam, nor any inside the shell after I removed it.

So, whodunnit? I am not inclined to believe it was lack of lighting. I have 400W 20kK MH for my 58 gal display, and the clam was in direct light. It did often seem pestered by my hogfish, however, and would frequently close up when the hogfish swam by.

Thanks for any ideas and suggestions to avert future clam deaths!

Jason

 

[organism]

although it may be the hogfish, my bet is on the water quality, clams need very crisp conditions, and a fluctuating alk level would likely finish one off, as well as the low salinity, usually anything under 1.25 will stress out clams quite quickly. I'd say hold off on getting another one for at least a few months, until you can keep the levels balanced, otherwise you're going to lose the next one too...

 

[bromion]

Certainly I would not get another one soon. Keeping high salinity always seems to be an issue for me. Over what period of time is it safe to raise it from 1.022 to 1.025?

 

[Peabody]

Agreed that 1.025 is crucial for clams....also even at 6.2 your ALK is still WAY too low...that's under NSW levels. Most people choose anywhere between 8-11.5 DKH (though that's a debate for another thread)

I would go up one pt. a day for that salinity. I'm sure you could go faster, but I play it safe. Just curious, why is keeping high salinity an issue for you?

 

[bromion]

I don't know why it is an issue, really. I have a freshwater auto-topoff, so maybe I am losing a lot of salt in skimming or creep, and it is replaced by freshwater.

 

[organism]

<a href=showthread.php?s=&postid=7896746#post7896746 target=_blank>Originally posted</a> by bromion
I don't know why it is an issue, really. I have a freshwater auto-topoff, so maybe I am losing a lot of salt in skimming or creep, and it is replaced by freshwater.

that's most likely your issue right there, keep a close eye on the amount of water removed through skimming, and try to replenish that water with salt water manually, it may help... I actually have the opposite problem, and continually find myself battling a 1.27 salinity, but the clams don't seem to mind

 

[bromion]

How about compatibility with soft corals? I was just informed many soft corals are toxic to clams. I have two Sinularia sp. a few mushrooms, and star polyps. Could these have contributed?

 

[swimboy123]

I have had a sinularia triple in size next to 6 Tridacna clams with no problems ever.

 

[bromion]

swimboy123: how big is that tank? I have only 60 gal of water in this system.

 

[scarter]

my clams are actually touching my GSP. for months, no problems

 

[Clamaholic]

I have never had or seen any problems between clams and soft corals. Your problem was definately related to your water parameters. I have found that with stable conditions clams are really hardy and low maintenance. Work on stability and the clams will thrive. I have a 55gallon three clams and SPS, softies, shrooms you name it.
Stability is the key.