Why do inverts die off over time?

[Dom]

I put about 50 hermit crabs in my tank, back in the fall. Now, their shells litter the substrate and few are left.

I noticed this pattern; that inverts don't last long term in my tanks... I'd say less than a year.

Wondering why this is and what to look for.

 

[Spare time]

Maybe not enough food?

 

[ISpeakForTheSeas]

I put about 50 hermit crabs in my tank, back in the fall. Now, their shells litter the substrate and few are left.

I noticed this pattern; that inverts don't last long term in my tanks... I'd say less than a year.

Wondering why this is and what to look for.

Some things to check generally and with hermits specifically:

-Are you feeding them enough and a good diet?

-How is the water in the tank? Are you using RODI? Any contaminants like Copper?

-Do they have enough places to hide away from each other and any fish so they can do things like molt safely?

-Do you have anything that might prey on them in the tank?

-Do you have enough shells in different sizes of the right variety for the hermits to grow into and accept? (Hermits can be quite picky about what shell's they use).

 

[vetteguy53081]

Im many cases, low calcium, High phosphate levels, starvation and some from falling and unable to invert themselves

 

[VintageReefer]

They fight each other to get shells. And most of the time people buy too many and they starve

 

[Peair]

Maybe not enough food?

 

[Fishy Fish]

I put about 50 hermit crabs in my tank, back in the fall. Now, their shells litter the substrate and few are left.

I noticed this pattern; that inverts don't last long term in my tanks... I'd say less than a year.

Wondering why this is and what to look for.

50 ??? Dude how much is too much ? it's hermit crab ,the more you own the more casualties the will try to kill each other for the shell

 

[Dom]

Some things to check generally and with hermits specifically:

-Are you feeding them enough and a good diet?

-How is the water in the tank? Are you using RODI? Any contaminants like Copper?

-Do they have enough places to hide away from each other and any fish so they can do things like molt safely?

-Do you have anything that might prey on them in the tank?

-Do you have enough shells in different sizes of the right variety for the hermits to grow into and accept? (Hermits can be quite picky about what shell's they use).

I don't feed food specifically for inverts. Their job is cleanup; to sift through the substrate and pick out the tiny bits that get lost in the tank.

The water quality in my tank is impeccable. The tank is thriving. As of Sunday 1/14, parameters are as follows:

• Salinity- 35ppt.
• Temp- 76.6
• Phosphorus- present.
• Nitrates-10
• Calcium- 440
• Alkalinity- 8.4
• Magnesium 1460

There are plenty of hiding spots and I have observed one move to a new shell.

 

[Dom]

50 ??? Dude how much is too much ? it's hermit crab ,the more you own the more casualties the will try to kill each other for the shell

"Dude"... the tank is 125 gallons. There is a LOT of rock and substrate for them to sift through.

 

[Cthulukelele]

My opinion is starvation or predation. Shell growth is a pretty negligible calcium need in a bigger tank. I can count on one hand how many snails I've lost over the years outside my crash where most things died.

People generally overstock inverts imo to get a "clean" look to their tank

 

[Troylee]

"Dude"... the tank is 125 gallons. There is a LOT of rock and substrate for them to sift through.

I got about 10 in a 275 and haven’t lost any! They’re huge now lol! I call them the little gang bangers of my reef since they’re always jacking snails for shells! Hahahaha

 

[Cthulukelele]

I got about 10 in a 275 and haven’t lost any! They’re huge now lol! I call them the little gang bangers of my reef since they’re always jacking snails for shells! Hahahaha

Yeah I have probably 8-10 in a 120 and if I could I'd have a few less. They're all huge now.

 

[ISpeakForTheSeas]

I don't feed food specifically for inverts. Their job is cleanup; to sift through the substrate and pick out the tiny bits that get lost in the tank.

The water quality in my tank is impeccable. The tank is thriving. As of Sunday 1/14, parameters are as follows:

• Salinity- 35ppt.
• Temp- 76.6
• Phosphorus- present.
• Nitrates-10
• Calcium- 440
• Alkalinity- 8.4
• Magnesium 1460

There are plenty of hiding spots and I have observed one move to a new shell.

Yeah, no issues with the parameters there, and I took a glance at your build thread and it does look like there a lots of spaces to hide.

So, given that you still have a few left and you don't feed them specifically, I'd personally guess (possibly incorrectly) that the few you have left are the ones that were able to scavenge enough food to survive - so that's probably a good approximate maximum for how many hermits your tank can support based on your current feeding levels (assuming the hermits aren't full-size, I'd expect the numbers to drop a bit more as they finish growing).

 

[themcnertney]

Do you have any carnivore fish. Im learning recently that my dottyback has killed all my hermits.

 

[Cthulukelele]

Yeah, no issues with the parameters there, and I took a glance at your build thread and it does look like there a lots of spaces to hide.

So, given that you still have a few left and you don't feed them specifically, I'd personally guess (possibly incorrectly) that the few you have left are the ones that were able to scavenge enough food to survive - so that's probably a good approximate maximum for how many hermits your tank can support based on your current feeding levels (assuming the hermits aren't full-size, I'd expect the numbers to drop a bit more as they finish growing).

I'd also say that hermits are sold as cohabitating with one another peacefully, but in my experience they first have to stake out claim on territory and actively try to murder each other during that time, so even if there is enough food technically in the tank, there isn't enough territorial space based on the aggressiveness of each individual hermit in the tank.

 

[Daniel@R2R]

I'm thinking 5-10 in a 125 gallon would be more than adequate. I think you just unfortunately overstocked them.

 

[Aquavaj]

Even for a 125 that's way too many. They're starving and likely killing each other.

 

[PeterErc]

It’s simple

stock the tank with a hundreds of snails Cerith, Astrea, turbo astrea, whelks, nerite etc of all different sizes.

food and shelter not an issue

Some wrasses eat hermits

At least you will know why all your snails are dying

 

[KrisReef]

My Tomato clown and Harlequin tusk beg me to buy them shellfish for dinner, but I am too cheap.

 

[VintageReefer]

My 75g reef has 6 snails, 10 scarlet hermits, and a conch.

50 is way to many imo. Unless your tank has some serious algae and detritus issues, they starved. And even if you did have serious issues with algae and detritus, once they clean it up, they will starve.