Dead sea... - Unexplained death of crabs and snails...

Z

Ziggy_Zeigler

[Hi -

I obtained a 70 gallon salt water tank a month and half ago. The tank came with about 70 lbs of live rock in a bucket with heater and power head. The sand was contained in a few buckets, but was dry.

I tended to the live rock (checking specific gravity, temp, etc.) while I set up the tank.

About 2.5 weeks ago, the tank assembly was completed. It has about a 35 gallon sump/refugium and 2x250W MH lighting.

The sand is about 3-4" deep in the tank and about 5" deep in the refugium. The live rock was transferred to the tank after 3 days of running. The sand was seeded with 20 lbs of live sand from another tank.

The tank was monitored on a daily basis with no measurable cycle for a period of 8 days.

Readings:
Temp - 78
Specific Gravity - 1.024
Ammonia - 0
Nitrate - 0
Nitrite - 0
pH - 8.2
alk - norm/high

At that point 2 crabs and 3 snails were introduced. These died over a period of 24 hours. A mushroom coral was introduced at the same time and is still doing fine.

Time elapsed with no measurable changes in the tank water. A sample was taken to the LFS to rule out incorrect testing methods or faulty test chemicals.

4 days ago, a 30 gallon water change was performed. In addition, activated charcoal was used on the tank. An interesting note is that the charcoal fizzed for about an hour after it's introduction. The charcoal was left on the tank for 48 hours.

It has been 2.5 weeks and 2 snails and 1 crab was introduced today. Within moments of contact with the sand, the snails died. The crab is noticably less active.

My current thinking is that my measurements are not detecting something in the sand. I am seriously contemplating moving everything to sump/refugium and replacing the entire sand bed. This is a huge effort, but I do not see any alternative at this point. Please note that the mushrooms are still doing great.

Thanks for any help, ideas, or corrections to my current dilemma.

Regards]
 
[Ziggy I live here in Lucas and will comeby and look at the tank with you. Maybe we could figure something out. PM if you want.
Rick]
 
[Can you detail how you acclimate your creatures? I doubt its the sand at this point, but 20 lbs of it is a lot of seed. I usually use only 2 to 4 lbs total. Two small cups worth.

As long as your nitrates are low, inverts should be fine.]
 
[The first thing I would look at is like Marc said about acclimation. I recently read that snails should be acclimated over a 5-6 hour period. I guess you are sure the snails were dead. I have added a lot of snails lately, some are moving before they hit the bottom. Some did not move at all for 24 hrs then they were fine. The speed that the snails and crabs die seems to indicate a drastic shock.

Is the "live rock" "Live" or are the mushrooms the only thing really surviving. Was the tank a reef tank before or a fish only with live rock. Is there any chance that the tank has a copper or other metal that you haven't tested. Metals can remain in the sand bed and rock if the tank was ever treated/contaminated. (I doubt it since the mushrooms are ok.)

Keep us posted.]
 
[@Marc wrote:
Can you detail how you acclimate your creatures? said:
The acclimation is similar each time:

1.) Float 1 hour
2.) Add 1/2 cup tank water
3.) Float additional 15 minutes
4.) Repeat steps 2 and 3 two more times.
5.) Pull snails/crabs from bag and place on rocks.
6.) Wait a few hours (they are usually moving around on the rocks).
7.) Place them on sand bed.
8.) They die.

Hope that helps]
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[

terry wrote:


"I guess you are sure the snails were dead. "

Well, the original ones have not moved in about a week (and I removed them and they smelled horrible). So I would guess they are dead.

The ones added yesterday have not moved since I placed them in their spot and it has been 24 hours.

The live rock does have a few of those tiny feather duster worms. I have not seen much activity beyond that. The tank had corals and zoos in it originally.

Let me know if that triggers some thoughts.]
 
[Ziggy, I just lost a lot of my snails, and it was from ammonia in the RO/DI water. You might want to test, as my mushrooms survived, but inverts lost.
I also thought copper; you might want to add a polyfilter pad and see if it changes color. If there is something in the water, the pad changes color really quick (in case you didn't know about them). That would be my suggestion.]
 
@kitty32 wrote:
[Ziggy said:
[The tests are still coming out as appropriate (I just finished another round of testing).

pH - 8.3
alk - norm/high
specific gravity - 1.025
ammonia - 0
nitrate - 0
nitrite - 0

I have not heard of polyfilter pads. I will stop by the LFS tomorrrow and investigate.

Thanks]
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[Ziggy

This sounds like you have some nasty chemical in the water. The deaths are coming too fast for it to be anything else. Have you tried adding a water conditioner which "binds" onto heavy metals etc? Maybe this will help.
I know its mean, but you could also try a damsel, just to confirm that the water is bad.]
 
[???
Hate guessing games, but?, Metal's?
Snails die quick from copper and so on/brass fittings leaching metals into the water. I would replace all the water before the DSB, and give your rock a RO wash as well, if you decide to do this.
Your tank is not that old, maybe a 3/4 water change? You would at least see if it is the water that is the problem for the snails.

Good luck,
m]
 
@ReefGeekers wrote:
[??? Hate guessing games said:
[I am now down to trying something drastic. The RO/DI unit is working overtime to help me make a huge water change and I have several bags of "new" sand to possibly replace the DSB.

I really appreciate all the great ideas and helpful hints. A fellow from the club (Rick) was kind enough to come over the other night and take a look at the setup. He made some helpful suggestions that I will try to incorporate this weekend.

I am trying to do this in stages so that I may discover the magic bullet.

Thanks]
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