Mass Emerald Crab Death and 2 brain coral

[kzitzman1]

I’m at a loss so I’m going to ask the community. We have a 125 gal tank that has been stable she’s for over a year. We love emerald crabs and typically have 4-5 of them in the tank. Recently we’ve had a rash of them dying including the new ones. We’ve lost at least 4-5 and have 1 left. Anyone have an idea why?

Background: all water parameters seem fine: phosphate, alkalinity, ammonia, etc are all great. Nitrate is at 20 maybe. Our tank is very friendly with no fish that give issues to any inverts (we got rid of the Melanarus before this issue started). We have several other hermit crabs, a Halloween crab, 2 blue knuckle crabs, snails and 4 cleaner shrimp and they are all great. No fish have died and all of our coral (only LPS coral) are doing great EXCEPT both of our brain coral also suddenly and quickly died. We are also stumped by both brain coral dying and can’t figure that out either.

why would so many things be doing fine - coral, fish and inverts - yet the emerald crabs and two brain Coral’s suddenly die?

 

[kzitzman1]

I’m at a loss so I’m going to ask the community. We have a 125 gal tank that has been stable she’s for over a year. We love emerald crabs and typically have 4-5 of them in the tank. Recently we’ve had a rash of them dying including the new ones. We’ve lost at least 4-5 and have 1 left. Anyone have an idea why?

Background: all water parameters seem fine: phosphate, alkalinity, ammonia, etc are all great. Nitrate is at 20 maybe. Our tank is very friendly with no fish that give issues to any inverts (we got rid of the Melanarus before this issue started). We have several other hermit crabs, a Halloween crab, 2 blue knuckle crabs, snails and 4 cleaner shrimp and they are all great. No fish have died and all of our coral (only LPS coral) are doing great EXCEPT both of our brain coral also suddenly and quickly died. We are also stumped by both brain coral dying and can’t figure that out either.

why would so many things be doing fine - coral, fish and inverts - yet the emerald crabs and two brain Coral’s suddenly die?

I should also add that I did confirm they died and weren’t just molts. Also we had most of them for several months.

 

[Seymo44]

Do you have algae? Lack of algae could potentially contribute to the death of the crabs. These crabs are omnivores but still need algae in their diet.

 

[kzitzman1]

Do you have algae? Lack of algae could potentially contribute to the death of the crabs. These crabs are omnivores but still need algae in their diet.

Yep, well established and has some algae plus I give them a piece of algae when we put it on the clip for fish.

 

[Seymo44]

Have you used copper?
I would try checking on them during the night to see if you notice any aggression between the crab and something else. Other than that I’m stumped.

 

[MaxTremors]

What are your exact parameters and are they stable? What kind of ‘brain coral’ are we talking about? Did you start your tank with real live rock and is it possible you have a mantis shrimp or other hitchhiker? Are you dosing anything? What are all of the tank inhabitants? Just need as much info as possible to try and narrow down potential causes. Have you used any insecticides in the house or other aerosols around the tank?

 

[vetteguy53081]

One corellation I see is calcium needs for both.
What test kits are you using and what numvers are you getting when you say numbers are good ?

Temp range 77-79
ph 8.1-8.3
salinity 1.025
ca 440
alk 8-11
mag 1300-1350
phos < .04
nitrate around 10-15

 

[Skynyrd Fish]

Time for an ATI water test. My bet is copper or another toxic metal. metals are a slow leach over time. good Luck.

 

[pbrown]

Check your sump and tank for "oddities". Last week I found the door spring mechanism had popped of my Red Reefer tank and landed in my sump. As I pulled it out there was rust on the mechanism....
That was the answer to my frogspawn and elegance not looking great the last week or so.
I did a large water change, sucked out the section of sump where the mechanism landed and a few days later the corals are looking better. I did lose my rainbow monitpora.

Feel like there is always something.... :|