My tank kills snails and crabs. HELP!!

BandJ · Oct 1, 2015

Ok long story short.... Started about a year ago with our first marine aquarium, its a 75g going great. In February we decided we wanted bigger and better tank for a reef so went and bought a complete setup from local salt water aquarium specialty store. It's a 125 with dual overflows, a wet dry sump rated for up to 300gal, eshoppe sump protein skimmer, and 1200gph pump. We added 120 pounds live sand, and I believe 25 pounds live rock and 75 dry rock (not positive on exact amounts without looking it up. Profile pic is of the tank). Things seemed to be going good, tank cycled, gradually added a few fish then lost a couple fish. In may we added snails and crabs and all DIED within 12 hrs. At this moment I freaked and set up another small tank and pulled the two clowns out that just put in outbof fear tank was being lost. Tests never showed anything abnormal. Did research and came up with copper poisoning so bought that test but nothing. Investigated power plug and discovered no ground last week so ran a ground wire. At this point we are happy, decided it was stray current that killed them. Bought 3 snails and 3 crabs and they too died over night except one ittie bittie blue crab. But our chromies and a sailfin tang have remained in this tank the whole time without any apparent issues.
Here is what the tank tests at.......
Temp 77
Salinity 1.023
Ammonia 0
Nitrites 0
Nitrate 20
Ph 8.0
Calcium 560
Kh 6
Phosphate .25
Copper 0

Any help would greatly be appreciated we are at a total loss and about to drain and start completely over.
PS: water comes from our ro system and we are having great success with 75g and 29g.

KorL · Oct 1, 2015

were the dead snail and crabs all scattered around the tank or in one area? My first thought was maybe there's a mantis shrimp in there

kylyb · Oct 1, 2015

or a bobbit worm.

twilliard · Oct 1, 2015

How did you acclimate them?

tripdad · Oct 1, 2015

Both of these critters can be sensitive to rapid changes in nitrate levels, yours are fine for fish but kinda high for inverts, they can take it but need a slow, long acclimation when there is a big change. I always test the water in the bag so I know where they are starting from compared to my tank. Just an idea to consider.

BandJ · Oct 1, 2015

We lost snails and crabs several times in this tank. First time we spread them out but this time in one spot to be able to track movement. As for acclimation we have used the ¼ cup every 15 minutes method and have done the drip method over night.

BandJ · Oct 1, 2015

The first time we lost them nitrates were lower.

twilliard · Oct 1, 2015

BandJ said:
We lost snails and crabs several times in this tank. First time we spread them out but this time in one spot to be able to track movement. As for acclimation we have used the ¼ cup every 15 minutes method and have done the drip method over night.

Hmm this is a head scratcher
And no copper right?

BandJ · Oct 1, 2015

We bought the API copper test and it shows zero. I did read tho in one article that not all tests will register low enough levels

BandJ · Oct 1, 2015

Have also tried different breeds and sizes of crabs and snails.

twilliard · Oct 1, 2015

BandJ said:
We bought the API copper test and it shows zero. I did read tho in one article that not all tests will register low enough levels

True!
But then if the tests did show copper I don't think it would be detrimental to them.
At one point in my tank I had 14 ug/l

tripdad · Oct 1, 2015

Can we get a complete list of whats in the tank ?

BandJ · Oct 1, 2015

1 sailfin tang
2 blue chromies
1 itty bittie blue crab

tripdad · Oct 1, 2015

Wow, not much of a clue there. The only time I have experienced death during acclimation was from elevated nitrate and phosphate levels I failed to catch, It was a batch of peppermint shrimp. By any chance did all the livestock come from the same source?

BandJ · Oct 1, 2015

No we have purchased from two different places

BandJ · Oct 2, 2015

Sadly I think the next step is gonna end up draining system, trashing the sand, boiling the rocks and thoroughly cleaning whole system to start over...

Justiful · Oct 2, 2015

BandJ said:
Sadly I think the next step is gonna end up draining system, trashing the sand, boiling the rocks and thoroughly cleaning whole system to start over...

Don't. There is 1 more thing you can do. No one does it usually except as last result because it cost 50 bucks. You are at that point. http://www.amazon.com/Triton-Labs-ICP-OES-Water-Elements/dp/B0106D3QAQ/ref=sr_1_11?s=pet-supplies&ie=UTF8&qid=1443797717&sr=1-11&keywords=aquarium+test+kit&refinements=p_36:4800-5000

Do the test and post the results. Then post it in chemistry forums and ask what is wrong.

Another probable cause is your water vs the fish store water. If there is a big difference in salinity a lot of inverts like snails will die within a week. Drip acclimate if you suspect a large difference. I would buy another snail and do this while waiting on your test results.

Another possible explanation is something added to the tank at LFS to treat parasites. Even if non copper based. Make sure that as little LFS water ends up in your tank as possible when adding livestock.

Another explanation is your copper test is wrong. Cupramine is a medication that is undetectable by some standard copper tests like API but will show up on http://www.amazon.com/Lamotte-Compa...id=1443799056&sr=1-7&keywords=copper+test+kit

Snails are about $1, so you can test 2-3 sources easily to see if it is just a bad source.

Kworker · Oct 2, 2015

Try floating a container or getting an acclimation box and putting the snails/crabs in there and see if they die.. If they live than you may have a culprit killing them... if they die its either something your doing wrong or something in water affecting them.