Why are my crabs dying?

[Nukeproof]

I have a 125 G tank with 150lbs of cured LR and 60lbs of LS. The DSB is in my refugium. I'm in my 8th week of cycling my tank. I have 1 false clown for over a month, 2 watchman gobies for about 3 weeks and second clown for 2weeks and a lawnmower blenny for less than a week. They are all doing find but I lost almost all my blue legged hermit, my emerald crab, 4 shrimps (2 scarlet and 2 fire). Lost only about 3-4 snails. I have one emerald left, he's been with me for over 3 weeks and a couple of horseshoe crab in my sand. What am I missing?

Also, I haven't had too much with corals either. An open brain and a mushroom had died on me and my star polyp and zoo haden't fully open. Using JBJ PC at first but just changed to 4 X 140W VHO, running on Ice Cap this weekend. I have another hairy mushroom that shrinks under my new VHO lighting so move it to the corner of the tank.

The LFS said everthing should be OK, even took water samples to various LFS to test my water. Been doing 10G water changes every 2 weeks and supplementing with Seachem Reef Builder, Turbo Calcium, and Reef Plus.

Ammonia=0
Nitrite=0
Nitrate=0 (Last week)
Calcium=450
PH=8.0 (Took it yesterday morning)
DKH=8-9
SB=1.023

I take between 45 minutes to 1.5 hours to acclimate my livestock.

Any help will be appreciated.

[mikrok]

I wouldnt have that livestock in there after only 8 weeks...other than a cleanup crew...

just my thoughts, but i think the lawnmower should have been introduced at a later time to allow for the tank to mature more, as well as with the corals and shrimp

also someone can hop in on the lighting of your tank but 4.8 wpg seems a little low for the open brain, but were the mushrooms, star polyps and zoo's touching the brain? they may have been in contact with the sweaper tentacles

[Nukeproof]

Yah, I was a little nervous about putting the shrimps and corals in but my LFS said it was OK. I'm going to be more cautious about what he says now. Except for the 2 clown fish, my main purpose of bringing the rest of the crews was to clean my major algea problem. Should I still add more crabs and snails or should I just keep it status quo for 3-4 weeks? I have about 18 trocus and 18 astrea snails. Only sees about 4 hermit left ( put in about 40), 1 emerald, 2 horseshoe.

[SBGRAD24]

Have you used any copper-based medications in the tank? Copper kills inverts. IMO you shouldn't have put any fish in the tank until it was fully cycled.

[shocksta]

For an 8 week old tank, you are introducing way too much too quickly. You describe adding 5 fish in a month's time... starting around your 4th week - that is too much IMO. I would back off and add no more. As for your crab deaths, I don't know what it could be.

Don't listen to your LFS, they are driven mainly by profit... not what is best for the livestock.. unfortunately.

[BarryF]

I agree that you're adding too much, too fast. However, that might not be the sole cause of your grief.

Your crab, shrimp, and snail deaths might be caused by an unwanted hitchhiker. I would definitely explore other avenues for an explanation, but I would also do little late night flashlight scavenger hunts to see if you have any unwanted guests.

Additionally, if you cannot figure out what's causing this other than too much too fast, since you are having problems with inverts and corals, I might suggest that you get a copper test kit and see if you somehow have copper in your water.

[Nukeproof]

Thanks for your opinions guys. I will definatly go out and get a copper test kit today. I haven't added any supplement except for the Seachem products and some Kent phytoplex(?) and ivert food. That was only done by spraying it with a springe.
FYI. I hired a maintenance guy when I set the tank up and was also following his opinion on when to add livestock. The rock I bought was from Tropical Paradise which was totally cured for months (It's another LFS that I use and trust). Even the maintenace guy told me that I should have a really short cycle because of the rock I got. Also I haven't seen anything living in my refugium either (except for a snail I put in to control my algea).

[Nukeproof]

One more thing, I've been using a 5 stage RODI unit from Air Water and Ice since I started up the tank. So I don't think there is copper in my makeup water.

[shocksta]

My vote goes for the hitchhiker theory in that case.... maybe a Mantis.

[bobafet1]

maybe there's not enough algae for the crabs to eat and they're just starving to death. If you have a mantis you might hear clicking noises at night.

[Xanareef]

Are you finding empty shells?

My hermits hide for a week and a bit after they shed, so we see skeletal remains, and no shell, then they creep out and start being saucy again.

The snails could be biting it by the rather agressive blue legged's that havn't molted.

[traveller7]

Originally posted by bobafet1
maybe there's not enough algae for the crabs to eat and they're just starving to death.

A very real possibility.

Originally posted by bobafet1
If you have a mantis you might hear clicking noises at night.

Typically pistol shrimp and snails(shaking blue legs and other snails off the shells) are the night time clickers. I have 3 mantis shrimp and they are silent at night. If the hermit shells are cracked and broken, then start looking for mantis shrimp.

[Nukeproof]

I think I got enough algea in my tank, the reason I keep adding crabs is that there are still a lot of algea on the sand, rocks, and glass. Most of my snails are doing fine except for my Trochus snail falling over. I think I only lost one astrea snail.
I didn't want to bring in a lot of cleaners in the first place, fear of them starving, so I only brought a total of 40 snails and 40 crabs. For a tank my size, I think the recomendation is 2 cleaners per gallon which would have been a total of 250 cleaners.
As for the Mantis Shrimp theory, I don't think I have one because there are no signs of crack shell and the dead crabs are usually out their shell lying on the sand bed until I take it off. My dead emeralds stop moving and there are no signs of any creature touching it. I brought them in twice now and they usually last only a couple of days. There is one emerald that I have for over 3 weeks now.
Also, I bought totally cured live rock and live sand that was in the bags so I don't even see sign of life on the rocks or sand even up to now. I observe my tank frequently even in the dark.

[GroYurOwn]

If you are still going through algea blooms on your sand its either diatoms or cyano bacteria, which means youve still got a while yet before your tank is cycled, maybe your crabs just cant handle the fluctuations going on in your tank. its not very scientific i guess, but after setting up three of my own tanks, i would just wait the algae blooms out, the snails you have in there should take care of what doesnt just go away on its own, and then once your through the blooms, maybe consider crabs again. but IMO i thinks the snails are a lot more important than the crabs, i think you could do without them completely.

[ladybug]

hey all,
im going to horn in here with a question if you guys dont mind,
if i just found a red legged hermit without a shell , i guess that means he molted or got pulled out by another crab, correct? if he had just died he would have stayed in the shell ?
thanks ladybug

[traveller7]

Originally posted by ladybug
hey all,
im going to horn in here with a question if you guys dont mind,
if i just found a red legged hermit without a shell , i guess that means he molted or got pulled out by another crab, correct? if he had just died he would have stayed in the shell ?
thanks ladybug

If you have other hermits, they will likely pull a dead hermit out of the shell. It is more likely the hermit molted, you are looking at the shed exoskeleton, and the live hermit is in the shell letting his new exoskeleton harden. Good luck.

[ladybug]

i thought that was the case, you can kind of see thru it a little, and besides there's not any "critters" eating on it.
thanks for the answer

[Nukeproof]

Thanks GroYurOwn, for the advice. I think I am going to chill out for a couple more weeks. I guess the algea bloom was driving me nuts and I should have let nature take it's course.

[jfloydr]

I just added 5 red legged hermit crabs to my tank today. They are the only things in there except for a few hitch-hikers that came on my live rock (a few snails). I'm going to add more later. Should I buy some extra shells that are bigger and put them in the tank incase they outgrow the ones they are in. My LFS has a bucket of bigger empty shells for this.

[GroYurOwn]

definitely get extra shells, not only do the crabs need them, but it is pretty amusing watching them change from shell to shell, i have had crabs that would change shells almost everyday, its sometimes like watching them window shopping the shells.

[kmoses]

I recently had a similar die off off Hermits and snails.
I checked my copper and it was fine but the next day I
happened to go down the stairs and caught my Clarkii clown
picking my last one out of his shell. That's when I did some reserch and found that some clowns will feed on small inverts.
So that might be something else to look into for Ya.