Blue Leg Hermit Crabs

[SeaHorseQueen]

Hi, I was looking at how to stick my tank. It’s a 20g H. Right now I don’t have fish and my tank is still working out the bacteria bloom so until then I’m wanting some expert advise on these guys and pair up suggestions. I don’t have corals or algae that I see yet.

How often do you provide bigger shells and best places to find them
Will they harm juvenile clownfish or baby mandarin dragonets (bonus question)?
When is a good time to add them?
For pairing I wanted to see about cleaner shrimp or a pistol. Pros and cons?
Do I absolutely have to have a snail? I’ve dealt with pond snails and just don’t want to deal with snail babies.
Thanks in advance!

 

[blaxsun]

I put the odd small shell in my tank for them to "test drive". My LFS is a good source for shells. Nope - they definitely leave all fish alone. Two is probably a good number initially for your tank. Supplementing them with a small piece of seaweed once or twice a week will keep them fed until there's more for them to scavenge.

You'll find you have less tank maintenance with snails, and a good initial choice is trochus snails.

 

[Sharkbait19]

Blue legs are harmless in my experience. I don’t really add shells, they make use of dead snails (they may have killed some) and extra crab shells. The lfs could probably give you extra shells. You can also buy them online.
Hermits can only catch dead or dying fish.
I started adding them a week in, basically once there is algae you could get away with adding them.
Cleaner shrimp don’t pair with fish - tiger or candy cane pistol shrimp pair with specific gobies. Neither are a problem with hermit crabs, though the pistol may occasionally borrow them to fortify it’s burrow. It will throw them back out shortly.
You don’t need a snail, but they are a very good addition to the tank and help keep it clean. Pond snails breed at a much faster rate than most of the marine snails, and very few make it to maturity in saltwater between predators and filtration.

 

[SeaHorseQueen]

Blue legs are harmless in my experience. I don’t really add shells, they make use of dead snails (they may have killed some) and extra crab shells. The lfs could probably give you extra shells. You can also buy them online.
Hermits can only catch dead or dying fish.
I started adding them a week in, basically once there is algae you could get away with adding them.
Cleaner shrimp don’t pair with fish - tiger or candy cane pistol shrimp pair with specific gobies. Neither are a problem with hermit crabs, though the pistol may occasionally borrow them to fortify it’s burrow. It will throw them back out shortly.
You don’t need a snail, but they are a very good addition to the tank and help keep it clean. Pond snails breed at a much faster rate than most of the marine snails, and very few make it to maturity in saltwater between predators and filtration.

How often will they breed?

 

[SeaHorseQueen]

I put the odd small shell in my tank for them to "test drive". My LFS is a good source for shells. Nope - they definitely leave all fish alone. Two is probably a good number initially for your tank. Supplementing them with a small piece of seaweed once or twice a week will keep them fed until there's more for them to scavenge.

You'll find you have less tank maintenance with snails, and a good initial choice is trochus snails.

Will this add a lot of ammonia with the seaweed? I even never fed it before.

 

[Sharkbait19]

Will this add a lot of ammonia with the seaweed? I even never fed it before.

Seaweed does not add ammonia, and the waste produced by pretty much any cuc member is negligible.

How often will they breed?

Kinda depends. You may see spawning rather frequently but not much offspring out of it. I don’t have a real number for it but it’s certainly much less than pond snails.
Btw, pond snails are really easy to control if you’ve got a population of snail eaters like puffers or loaches.

 

[blaxsun]

Will this add a lot of ammonia with the seaweed? I even never fed it before.

As @Sharkbait19 indicated, it won't add ammonia. I like Two Little Fishies SeaVeggies green, so just take a 1/4 sheet and fold/wrap it to a small rock with an elastic band. If they haven't consumed it within a few hours just pull it out, let dry and re-introduce another day.