Where are my inverts going?

I added 2 peppermint shrimp, 1 cleaner shrimp, 2 emerald crabs and 1 sallielightfoot about 6 weeks ago. 1 PS and 1 emerald died in the first week and I removed them but the others have one by one disappeared. The cleaner was the last to go when I was out of town this weekend . No sign of any carcasses, etc. I only have a clown fish, some snails and some hermits in the tank right now so where did they go? All water levels are in good shape.
Any ideas as to what is going on ?

Thanks!

 

Is the tank grounded?

 

Everything is plugged into surge protectors that are plugged into a GFCI outlet.

 

wow. you might check for iodine those inverts need it to shed and grow. if they died your clean up crew could have them eaten quickly i think. just a guess.

 

Sorry, what I meant by "grounding" is by the addition of a ground probe in the tank or sump. Do you have one?

 

If regular water changes are being performed, iodine need not be added.

 

Sorry, I don't know what that is so I'm pretty sure that I don't have one. Can you enlighten me?

 

Ground probes redirect stray voltage out of the tank. Stray voltage is usually generated by electrical equipment that we use in and on our tanks such as lighting, powerheads, heaters, etc. You can find ground probes at most on-line suppliers or you can DIY one if you want to save a few bucks. In my experience, the first sign that you have stray voltage in the tank is when you start losing more sensitive inverts like shrimp, crabs, starfish and snails. Corals also stop extending polyps and generally look crummy when there's stray voltage in the tank.

 

Sounds like something I need to look into.
The next question is where are they going? Are the hermit crabs/bristle worms that efficient that they handle it that quickly?

 

Yes indeed! It also could be that they're eating the remains in a spot that you can't see.