Why do my Hermit crabs/shrimps keep dying?

jiffyjhn · Jul 22, 2021

I have a 2 month old AIO 32G. Currently it is stocked with:
2 clowns
1 firefish
some zoanthids and other corals
various snails,
brittle stars

Corals and livestock are all thriving. About a month in I added a cleaner shrimp purchased from Petco. Same day I moved a large hermit crab from my established 75 G tank. both the shrimp and crab died after 2 days.

Last week I started getting diatoms so I purchased some snails and 2 blue leg hermits from LFS. The snails cleaned up all the algae within a week and are thriving. the 2 hermits are lying upside down in the sand after a week. their legs are moving occasionally so they are not dead yet, but it is not looking good as they have not moved around in a few days. few days ago I added another hermit from my other tank, it was crawling around the tank for 2 days and is now also lying in the sand.

my parameters:
Salinity: 1.025
Ammonia: 0
Nitrite: 0
Nitrate: 5
PH: 8.0-8.2
temp: 26C

using Reef Crystal Salt
using ATO to Top off
4 gallon water change/ week
no additives.

My 75G tank has 1.021 salinity and my LFS has 1.022 salinity

shrimps and crabs were drip acclimated for about an hour before going in the tank

What could be the reason shrimps/crabs are dying?

Update: 1 of the blue leg hermits "standing"(not upside down) now, but still not walking around. The other one ditched its shell and is hanging onto an Acan coral.

Dkmoo · Jul 22, 2021

A few possibilities

1) improper acclimation - they are extremely sensitive to changing params, usually it takes me 6 hrs of drip acclimate to add them to my tank

2) starved to death. Seems your tank is still new so likely missing microfauna to keep it fed. When adding CUC to clean up algae, the mentality shouldn't be " do i see algae clearing up" and instead it should be "do i see algae stop getting more". Because, if your goal is to decrease the algae, then BY DEFINITION it means that your algae consumption rate is out pacing growth rate, so once it clears it up, it will run out of food and starve to death.

3) any chance new tank was used previously with copper medication? Could be leaking back copper which is toxic to inverts

Reef. · Jul 22, 2021

Dkmoo said:
A few possibilities

1) improper acclimation - they are extremely sensitive to changing params, usually it takes me 6 hrs of drip acclimate to add them to my tank

2) starved to death. Seems your tank is still new so likely missing microfauna to keep it fed. When adding CUC to clean up algae, the mentality shouldn't be " do i see algae clearing up" and instead it should be "do i see algae stop getting more". Because, if your goal is to decrease the algae, then BY DEFINITION it means that your algae consumption rate is out pacing growth rate, so once it clears it up, it will run out of food and starve to death.

3) any chance new tank was used previously with copper medication? Could be leaking back copper which is toxic to inverts

1 and 2 were going to be my suggestions too and 3 is a good call.

I would lean towards acclimation or the copper just because you say they are dying so soon.

Losirk · Jul 22, 2021

Most likely copper. Are you using RODI water?

jiffyjhn · Jul 22, 2021

Dkmoo said:
A few possibilities

1) improper acclimation - they are extremely sensitive to changing params, usually it takes me 6 hrs of drip acclimate to add them to my tank

2) starved to death. Seems your tank is still new so likely missing microfauna to keep it fed. When adding CUC to clean up algae, the mentality shouldn't be " do i see algae clearing up" and instead it should be "do i see algae stop getting more". Because, if your goal is to decrease the algae, then BY DEFINITION it means that your algae consumption rate is out pacing growth rate, so once it clears it up, it will run out of food and starve to death.

3) any chance new tank was used previously with copper medication? Could be leaking back copper which is toxic to inverts

1) Acclimated for about 1-1.5 hours using drip method. Though checking around on different threads, some reefers just throw them in without acclimation with no issues. I could try again with longer acclimation
2) there is still algae in the tank. some parts of the rock still has a brown tint to it.
3) the tank is brand new from FijiCube, I ran it for 2 days with RODI water before putting salt water in it to make sure it's clean. I have never copper treated any of the fish.

CanuckReefer · Jul 22, 2021

Dkmoo said:
A few possibilities

1) improper acclimation - they are extremely sensitive to changing params, usually it takes me 6 hrs of drip acclimate to add them to my tank

2) starved to death. Seems your tank is still new so likely missing microfauna to keep it fed. When adding CUC to clean up algae, the mentality shouldn't be " do i see algae clearing up" and instead it should be "do i see algae stop getting more". Because, if your goal is to decrease the algae, then BY DEFINITION it means that your algae consumption rate is out pacing growth rate, so once it clears it up, it will run out of food and starve to death.

3) any chance new tank was used previously with copper medication? Could be leaking back copper which is toxic to inverts

Yes....going with #2. In fact with a bullet.... this tank is young....breathe, it's ok 2 months? It's going to be a battle first year or two.

jiffyjhn · Jul 22, 2021

Losirk said:
Most likely copper. Are you using RODI water?

yes tested 0 ppm. although I keep it in the backyard in a brute trash can with the lid on. Not sure if something could have gotten in it.

CanuckReefer · Jul 22, 2021

jiffyjhn said:
yes tested 0 ppm. although I keep it in the backyard in a brute trash can with the lid on. Not sure if something could have gotten in it.

Its not copper....your tank is how old? ????

jiffyjhn · Jul 22, 2021

CanuckReefer said:
Yes....going with #2. In fact with a bullet.... this tank is young....breathe, it's ok 2 months? It's going to be a battle first year or two.

I thought this too, but that doesn't explain why the cleaner shrimp died too, he was eating when I fed the fish. Granted the shrimp was from Petco, not sure about the health of their livestock.
Still some Algae left in the sand

CanuckReefer · Jul 22, 2021

jiffyjhn said:
I thought this too, but that doesn't explain why the cleaner shrimp died too, he was eating when I fed the fish. Granted the shrimp was from Petco, not sure about the health of their livestock

I will explain it best I can. Your tank is 2 months. Stick with it, but you WILL see loses, and a few victories. Even after the cycle your slice of the ocean is going through major changes. Petco, depends on YOUR local retailer some are believe it or not responsible
...

Dkmoo · Jul 22, 2021

jiffyjhn said:
I thought this too, but that doesn't explain why the cleaner shrimp died too, he was eating when I fed the fish. Granted the shrimp was from Petco, not sure about the health of their livestock

Probably acclimation or change in params for the shrimp

For the hermits, I rarely see them eat the brown stuff. Mine really only picks on the very short new GHA sprouts and don't even touch the long strands, thats why they are good to maintaining a "clean" tank by cleaning up new growth, but not effective for reducing a already existing problem. Best bet for these is just manual removal, nutrient control, and/out out compete by other things.

They are also not that smart, tho they move, they dont always find where there is food

jiffyjhn · Jul 22, 2021

Dkmoo said:
Probably acclimation or change in params for the shrimp

For the hermits, I rarely see them eat the brown stuff. Mine really only picks on the very short new GHA sprouts and don't even touch the long strands, thats why they are food to maintaining a "clean" tank by cleaning up new growth, but not effective for reducing a already existing problem. Best bet for these is just manual removal, nutrient control, and/out out compete by other things.

They are also not that smart, tho they move, they dont always find where there is food

Thanks that makes sense. Flow is pretty strong in this tank, so the leftover from feeding the fish never gets dropped to the bottom. Might also be why they are starving.
I will try putting some nori on a clip and put it in the sand and see if they go for it.

Dkmoo · Jul 22, 2021

jiffyjhn said:
Thanks that makes sense. Flow is pretty strong in this tank, so the leftover from feeding the fish never gets dropped to the bottom. Might also be why they are starving.
I will try putting some nori on a clip and put it in the sand and see if they go for it.

Better yet, put them right on the sheet

I do that once a week whenever my tank feels like its "too clean"

DocRose · Jul 22, 2021

Alkalinity also plays a factor in certain invert's survivability in our systems.

alxrosco · Jul 22, 2021

It is strange that only the crabs and the shrimp are affected. it could be a virus/bacteria from the shrimp you purchased (?). Just like any animal, they could catch a disease. You can check the document of this link which relates to shrimp diseases. I would stop introducing crabs or shrimps for some period of time. You could also buy an sterilizer, but I would just wait.

https://nsgl.gso.uri.edu/tamu/tamuh95001.pdf

Reef. · Jul 22, 2021

DocRose said:
Alkalinity also plays a factor in certain invert's survivability in our systems.

Could be this, I know when my tank was young the alkalinity dropped very low for a few months.

jiffyjhn · Jul 23, 2021

Thanks for the replies! I will get a test kit for alkalinity.
Anything I can do for the crab that's out of the shell? currently I put him in a cup and put his shell beside him with some nori. He climbed onto his shell but not going inside.

Cantusaurus · Jul 23, 2021

Most likely they just did not acclimate well, and or parameters may have been slightly off. Drip acclimation is very important, and doing it for at least 20-30 minutes can really help, but you most likely did acclimate them properly

I would never recommend dumping them in straight away despite what other people say.
I am a bit confused on what the salinity is at since you said 1.025 and then 1.021. But either way as long as it is stable it should be fine. As long as there is some algae, detritus, or leftover food for them they should not starve.
Also which salt mix are you using? Or do you get store water? There could have been insufficient parameters of some kind.
The Nitrate test kit could also be off, and high nitrate spikes could be harming inverts that are acclimating.

Also high phosphates could be to blame for creating a lower oxygen and or negative bacteria that the inverts ate (not very likely but just a thought).

At the end of the day inverts just sometimes just do not do well. I do not know why. My peppermint shrimp I had for almost 7 months died randomly, and my porcelain crab died after 2 weeks in my tank despite good parameters, and having food and anemones in my tank.
Trochus snails also never do well in my tank even though there is food, and my nassarius snails and hermits are thriving.

Cantusaurus · Jul 23, 2021

jiffyjhn said:
Thanks for the replies! I will get a test kit for alkalinity.
Anything I can do for the crab that's out of the shell? currently I put him in a cup and put his shell beside him with some nori. He climbed onto his shell but not going inside.

I got the Red Sea Reef Foundation Test Kit for Alk, Calcium, and Magnesium, and the Alk test is SUPER easy, and accurate. The calcium and Magnesium tests are also very accurate, but take a bit more time.
Not sure about the hermit though

never experienced that, but as long as there are a couple shells to choose from he will most likely be fine. They can survive out of shells for a little while.