Ugh. Someone PLEASE help

[Klnsheree]

Are you freakin kidding me? This is the third and I mean THIRD time I have bought crabs/snails and they die within HOURS!
The first time we got ten blue leg crabs they lived all of two hours.
Second time we got two snails and five blue crabs. One snail never came out of its shell the other fell off the glass with in fifteen minutes and dies and the crabs died later that night.
Then today I got my fiancé a crab a snail a clown fish and an anemone. The snail stayed on the glass for about thirty minutes the went to the bottom and hasn't come back out so I'm guessing its dead and the crab crawled around for about an hour and now it's in its shell and hasn't come back out.
What the heck is wrong?
The Lfs tested my water and said everything was fine

 

[GrimReefer555]

My immediate thought is some sort of heavy metal... Has the tank been treated with copper? What your water source? Any living inverts?

 

[HumbleFish]

My immediate thought is some sort of heavy metal... Has the tank been treated with copper? What your water source? Any living inverts?

+1 Also, how are you acclimating them? Inverts should be drip acclimated, as they are more sensitive to changing water conditions. Still, hermit crabs are pretty bullet proof - unless there's copper in the water.

 

[kismetsh]

How long has this tank been set up? How was it cycled?

My advice is to never rely on an LFS to test your water and tell you it's "fine". You should invest in some test kits and learn what proper water parameters are. At a minimum write down your test results and post them here, someone may be able to spot something out of whack.

Heavy metal contamination is a possibility, especially if the tank was purchased used.

Definitely more info is required to try to determine a cause!