Hermit crabs - algae
Dear WWM:
If you were to choose 5 species of hermit crab or crabs in general, for routine cleanup of green hair and filamentous algae in my reef tank, which would they be?
I intend on having corals and want "reef safe" varieties.
I live in Ft. Lauderdale and can collect hermits from the tide pools.  Can I use these?  If so, what species...blue legged, red legged, etc
Thanks,
Steve
< I would do mainly red leg hermits.  Sally Lightfoots are good at eating hair algae also. Cody>

- Snails and Hermit Crabs Dying -
Hi:
<Hi, JasonC here...>
I have had my system up and running for almost a year now with no major problems. However within the last 2 months my snails and hermit crabs have been dying.
I have enough algae growing on the Live Rock to keep them busy. My Ammonia and Nitrates are zero and the PH is 8.4.
Any ideas on what could be wrong? <Probably nothing - most likely a form of natural selection at work, and none of these live forever... I wouldn't be too concerned.>
Thanks, Aram
<Cheers, J -- >

- Re: Snails and Hermit Crabs Dying -
Hi Jason:
<Hello again...>
Thanks for getting back to me. I checked my Ca level last night and it's down to 200, Could this be causing the dye off. <I doubt it.> Also my ALK is really high about 800 mg/l. <Egads, that is high, and would explain the low calcium.> I add 2 teaspoons of KENT Super Buffer once a week to maintain my PH, could this be a problem also. <Potentially... could be your water is already pretty 'hard' and doesn't need supplementation - stop adding the Kent product and test your source water.>
Thanks, Aram
<Cheers, J -- >

Cleaning Crew Run-Down
Ryan, thanks for taking the time to answer my question. <surely!>  I have read the FAQs re: sand sifters and decided against the sand sifting star. <You'll be glad, believe me.> This time around I would like to let the animals do most of the clean up work.  When I stated in the previous email "an assortment of snails", I was thinking about Nassarius, Cerith, Bumble Bee, Turbo, Trochus, and Astrea snails.  <Nice assortment, but you may starve this many snails without a heck of a lot of algae.  Turbo and Trochus seem to be the most productive in my tanks.  My bumblebees are a bunch of freeloaders!> I've read that these guys should help with the detritus and algae. <Yes, to an extent.>  Just how many do I need for a 125g tank?  <25-35 max.  Start with 15, add them as your tank matures.> Also, I've had a problem with Blue Leg Hermits eating my Astrea snails (not for their shells), and don't want this type of hermit again.  <Most hermits are opportunistic by nature.> My Scarlet reefers have never bothered any of my snails, and I like them a lot. Would about 50 of these guys be sufficient or should there be a mix of hermit species? <50 is way too many.  Try 20 to start, and see how this works.>  I was also thinking of a sleeper goby, but don't want to have him starve. <Skip it.  Not sure what kind of aquatic life you plan on keeping, but many fishes will take care of algae growth better than a sleeper goby.>  What would you suggest re: a clean up crew for a 125g?  <My "dream team," first off, would include a refugium.  Prevent the algae from growing by diminishing the available nutrients.  The snails and hermits sounds fine.  Look into opisthobranchs, commonly known as Sea Bunnies.  A great algae eater for bigger setups.  Also consider Cypraea annulus.  What I've found with grazers is that diversity is the key.  Each of these animals occupies a different niche in nature, and therefore in your tank.  The more diversity you add you cleanup crew, the less you'll have to intervene.  Talk to you soon! Ryan> Thanks again for your help and patience with my questions.

My hermits are becoming reclusive!  07/23/03
<Hi Chris, PF here with you tonight>
I picked up 9 "zebra hermits" (although I swear they're blue-legged hermits by visual identification) at the LFS for some hair algae control, as well as 4 Astrea snails. For the first few days, the hermits chewed away happily at the algae, and tended to congregate in small meetings.
It's been a week, and all the hermits have seemed to crawl into crevices in the LR. They all have their antennae (?) wiggling about on their faces, but they remain in there at leisure. Are these creatures nocturnal? I'm somehow doubting that. I know any aquarium won't live up to what my ideal 'bustling with life' scene might look like, but I was hoping for a little more action out of these guys. Should I be looking towards water quality issues? Everyone deciding to molt simultaneously?  The Astreas seem to be faring well, happily chewing away at the algae. 3 seem to be doing fine. The last one is quite lethargic, moving at a snail's pace, as it were.. I will be doing ammonia/nitrate tests in a few minutes.  pH is hovering at 8.2; s.g. at 1.024; temp ~82F.
P.S. Since I last wrote to WWM a couple of months ago, my so-called "hard cure" has long since become quite rewarding, and I could not imagine ever wanting to buy "fully cured" LR! Tons of creatures lurk in the depths of my tank, including strange translucent tentacles (approx 1mm in diameter) that shoot out of tiny holes in the LR and suck in detritus with their vacuum-cleaner like tips (any ideas on what that might be btw)?  Thank you for providing this wonderful service WWM crew!  Enjoying this hobby, even if I am making all the beginner mistakes one at a time, - Chris
<Well Chris, they could be blue legs in zebra snail shells. A rose by any other name... As for their behavior, remember, they don't read the same books we do. I've certainly seen my animals doing things that they're not supposed.  The critters on the rocks, are probably some sort of worm, maybe the spaghetti worm, check here for more: http:// www.wetwebmedia.com/polychaetes.htm   Mistakes, well, I try not to make beginner mistakes myself, but all new ones. ; ) At least it was one at a time, and not all at once.  Have a nice night, PF>

How many hermits - 10/14/03
     I'm a little confused. <Aren't we all?>  On the hermit crabs page, it says:
"If you use them, place about one, two small Hermits per actual gallon of your system. <Emphasis on small> Use a mix of species and make sure and provide many "upgrade" homes (empty shells) for your Hermits to move to." <I can agree to this view with the exception that the hermits should be small>
     However, on the first hermit crabs FAQ page, the first question reads:
"Snail & Hermit Crab waste
Hi Bob:
My tank finally cycled with a lot of algae bloom. Two days ago I added 10 Scarlet Reef Hermits 10 Turbo/Margarita Snails and 30 Red Leg/Left-Handed Hermits from FFExpress. They have done an excellent job cleaning but I noticed a lot of waste since I added them in the tank. Is this bad for the tank? And should I pull out some of the hermit crabs out?
<You neglect to mention how large your tank is. I would not use anymore than 1 hermit crab per 10 gallons. I use about 1 snail per 2-4 gallons depending on the tank, lights, etc.>
Thank You, Aram
<You are welcome. -Steven Pro>"
     So which one is it? <Well, I can see this view as well, different strokes for different folks. Let me tell you what I have in my ten gallon tank. Two hermits. That's right....two. Ask me how many I started with? Ten hermits of varying species. Aggression and starvation has eliminated the competition. So my recommendation is one no more than two per ten gallons period. The same equation works in my twenty gallon for the most part. I now have three left out of twenty. So maybe no more than four in a twenty gallon should suffice>  There's a big difference between one or two hermits per gallon, and one hermit per ten gallons. <Agreed. The above recommendation is what works for me. You might have luck with a few more if you feed them regularly. Is it a little bit more clear? Hopefully so>
     As you can see, I am confused. <Naw.......just a difference in point of view. You are gathering information for a better point of view. Good on ya' mate, -Paul>
     Brian

Detritivores and crabs 12/16/03
Oh Helpful Gurus-     I have *about* 3/4 of an inch of crushed coral substrate that needs more maintenance. I change water / siphon 4 gallons once a week in a 55 gal. I am thinking of getting something in the way of detritivores. I imagine this means snails. However, I have a hermit crab that is a pretty good size, perhaps 1.5". Am I wrong thinking the crab will eat any snails I introduce?  
<you are correct... the hermit is a calculated risk and likely to eat some desirable invertebrates. Few are truly reef safe.>
Is a crab this size just an all-around bother?
<yes>
I have a fish-only tank and plan to keep it that way, so the rest is not a problem. Small picture attached for fun and reference.
Thanks! Lance
<do consider instead one of those outstanding Amblygobius phalaena Bullet/Dragon gobies. Truly outstanding for sand sifting and hardy too. Anthony>

OTC algae attack packs
How's it going over there? <Hi Sean, MacL here.>
I was wondering if the algae attack packs which they sell (which include scarlet reef crabs, turbo snails, and dwarf red tip hermit crabs), would eat the beautiful coralline algae found on live rock. Do you think it is worth adding algae attack packs to aquariums with live rock? <I can only tell you that from my experience they will eat coralline algae.>
Sean F.

Cleanup Crew/Algae Control...and what else? More Mandarin trouble.  10/4/05
Good afternoon, Bob!
<Actually Adam J here with you tonight.>
I have found your website to be invaluable for information.  Thank you very much!
<Well it’s not my doing but I agree this place is awesome.>
I am the temporary keeper of a 29-gallon saltwater aquarium.  I know that it has more inhabitants than it should have for its size, but it's not my tank!  :-)  
<Sounds like you should show your “friend” the way of the force….I mean responsible aquarium keeping.>
However, I am wanting to control the algae & get some help with leftover pellet food cleanup!  <If there is a lot leftover you are over feeding.>  I recently purchased a horseshoe crab, which I now know from your website, was a mistake for this tank size.  <Yes.>  However, I also have a turbo snail & a mandarin goby in there.  <Whoa a Mandarin? Do you know the requirements of this species? It will surely starve in a 29-gallon tank within months.>  In considering hermit crabs and additional snails, can you offer suggestions?  <Trochus snails are a favorite of mine for algae grazing, though the best way to prevent algae is to remove the nutrients that are feeding them. Efficient skimming and frequent water changes should be employed.>  The most aggressive fish living in the tank are 3 damsels, so I don't think that will be an issue.  <An issue as far as what?>  But my concerns are these:  (1) the aggressiveness of hermit crabs as they outgrow their shells, and I wonder if there is a breed of crab that will work whose shell grows with him or who will accept a spare shell rather than attack others for a new one. <You should always have extra and larger shells for the hermits to choose from. This will help minimize the aggression. Hermits “rent” shells they do not grow with the crab.>  (2) How many crabs/snails will I need to control algae in this size tank? <The one turbo and a Trochus or two is more than enough. I prefer not to use hermits.>  (3)  How big will a hermit crab grow... will he outgrow the tank? <Depends on the species some stay dime sized while other can become softball sized.>
Your response is very much appreciated, and I look forward to hearing from you, Vicki Racette
<No trouble but please address the Mandarin, as it is not suitable for this set-up. Adam J.>

We Need Merry Maids!  11/12/2005
Hello WWM Crew,
I hope all of you folks are doing GREAT and as always, thanks for the wonderful website! I am almost completely cycled and getting ready to start stocking my 240 gallon reef tank and I think I have most of my livestock list figured out except my "cleaning crew". This has been the most confusing aspect of figuring out my livestock list thus far and was wondering if I could get some advice. 
My first question concerns the Nassarius obsoleta or Ilyanassa obsoleta. I was considering adding some of these to my cleaning crew for their glass cleaning, algae eating; sand stirring ability but I have read so many mixed reviews I am not sure what to do.
<"When in doubt, leave them out">
One person swears by them and the next person condemns them. I was wondering if you would give me your opinion and/or experience with them, whether or not you recommend them and if you do recommend them,
<Are useful creatures of utility for many types of marine aquariums, species mixes>
how many you would recommend for my 240 gallon tank?
<A handful, two handfuls>
I have 500 pounds of rock (250 pounds base rock/250 pounds live rock) and an average sand depth of 2". Also, I am including what I have come up with for a cleaning crew and I was wondering if you could advise me whether you feel this is appropriate for my setup or not and if I should add the N. obsolete along with this crew, substitute if for one of the other snails or leave it out all together. I haven't purchased any of these items yet because I don't have a LFS or anyone locally to ask advice and to be totally honest, you folks are the only source I trust when it comes to my reef tank. I also would like your opinion as whether I should add this cleaning crew first or should I add some of my other livestock first 
<They, the cleaner-uppers, should go in first>
and wait a few weeks before adding my cleaning crew so they won't starve on such a new tank. 
<Not likely with the LR>
Anyway, the cleaning crew I have come up with is as follows and please direct me as to whether you feel this is appropriate or as to what changes I should make. The list is as follows: (50) - Mexican Red-Legged Hermits Clibanarius digueti, (200) - Small Blue-Legged Hermits Clibanarius tricolor,
<Am not a big fan, okay even mid-sized fan of using Hermits, and not in large numbers... I would start with far fewer if you want to use these>
(120) - Turbo Snails Astrea sp., (120) - Nassarius Snails Nassarius vibex, (30) - Nassarius Snails Nassarius polygonatus, (30) - Nerite Snails Nerite funiculate, (120) - Cerith Snails Cerithium strercusmuscarum and (6) - Peppermint Shrimp Lysmata wurdemanni. 
<... this is way too many snails... by about an order of magnitude in my opinion/experience. Many will die off... polluting your water, others will "die mysteriously" consumed by the Hermits...>
I am sorry for such a long email but I just want to make sure I am on the right track before adding such a critical component to my reef tank. 
As always, thanks so much for your help!
Take care all,
Bryant
<Please read here: http://www.wetwebmedia.com/marscavart.htm and the linked files above... Do agree with you re differing opinions in this hobby interest... And mine is to scrub more, circulate, aerate and skim more... be careful re introduction of the means of algal and detritus production, and severely limit the introduction/use of such "cleaners". Bob Fenner>

Re: Establishing a new minireef tank
Thanks for your quick response; I don't know how you find time to respond to everyone.
<Fast keyer>
In terms of cleanup organisms do you have any favorites?
<Yes... all sorts... they're mentioned here and there on the www.WetWebMedia.com site sections, FAQ files>
Will urchins, sea cucumbers, Fromia stars or serpent stars do as good a job? 
<Not most Urchins for most types of tanks... some of the cukes are okay, some way too toxic/problematical, Fromia genus stars are fab, the Green Serpent Star is trouble in the long haul...>
Abalone? Emerald crabs? Are Hermit crabs reef safe as they get larger? 
<No to abalone... Mithrax, Hermits are covered on the WWM site>
Does one need to provide empty shells as they grow?
<Yes>
One last (probably not) question, if you don't mind, before I go. Your opinion regarding
U.V. sterilizers. My local retailer recommends that a sterilizer be used routinely for a system with inverts and fish due to the difficulty of treating fish in the presence of inverts. 
<It's a high ticket, margin item... No to preventing, curing disease... best approached from careful selection, quarantine, dips/baths angles... >
My concern is that the U.V. sterilizer will kill useful bacteria, algal spores, etc.
There is no apparent consensus in the literature.
<Keep studying... there is consensus of sorts... amongst people who know what they know and what they don't in/about this aspect of the marine hobby... UVs are useful adjuncts to otherwise well set-up, maintained systems... a few percent better in terms of DO, Redox, lower TBC's... they are not a panacea>
Thanks once again for your generosity with your time.
I Gross
<Press on, my friend. Bob Fenner>

Re: Cleanup Crew Question
Thanks for the Reply Anthony!!!
<very welcome, my friend>
I have a follow up question or two:
1) Are you saying I should get rid of the blue legged hermits?
<not at all.. I like them very much and use them often. We just have to admit that as a very efficient scavenging omnivore, they will exact some toll on the benthic microfauna. It you were obsessed/enjoyed viewing the DSB with a magnifying glass and really developing the bed to its fullest at the expense of say more nuisance algae, then the hermits have to be reckoned with. For most folks they are good and cheap detritivores>
2) What other inverts should I get to feed off of the algae and detritus?
<I prefer to not use many at all but maintain above average water movement (random turbulent) and conduct very aggressive protein skimming to export nutrients and starve algae out>
How soon should I begin adding more?
<just watch brown diatom algae growth and add as necessary to keep up with it if your skimmer is producing daily dark skimmate (4-8oz per 75 gall tank)
3) Please explain what you mean by mixing corals and emphasizing families within one type? Is there some succinct reading I can do that will go over this? Thanks again!
<really quite long to explain here. I'll be excerpting passages from my Book of Coral Propagation for the WWM site in the next few months. And Eric Borneman's book Aquarium Corals is very good with unique info on allelopathy/coral aggression. Bob did a review of my book here: http://www.wetwebmedia.com/bkcorlproprev.htm. One or both titles are available from some of the advertisers on the WWM site (Di's Aquatics, Custom Aquatic, etc). Kindly, Anthony>

Snail & Hermit Crab waste
Hi Bob:
My tank finally cycled with a lot of algae bloom. Two days ago I added 10 Scarlet Reef Hermits 10 Turbo/Margarita Snails and 30 Red Leg/Left-Handed Hermits from FFExpress. They have done an excellent job cleaning but I noticed a lot of waste since I added them in the tank. Is this bad for the tank? And should I pull out some of the hermit crabs out?
<You neglect to mention how large your tank is. I would not use anymore than 1 hermit crab per 10 gallons. I use about 1 snail per 2-4 gallons depending on the tank, lights, etc.>
Thank You, Aram
<You are welcome. -Steven Pro>

Re: Snail & Hermit Crab waste
Hi Steve:
I have a 54 gallon corner tank. I guess I should pull out some of the crabs and snails. What do you think?
<Yes, I would remove all but two of each hermit crab. I would leave all the snails and if you need more algae eaters, get ten more Astrea, Cerith, or Nerites snails. I like to use a variety of snails as they all seem to prefer to eat different things. -Steven Pro>

Re: Snail & Hermit Crab waste
Thanks Steve, FFExpress should redo their Web Site about adding the correct amount of Invertebrates. ~Aram
<Nothing in particular about FFExpress, but all of these places are in the business of selling. I never assume any salesperson, selling anything, knows everything about their product or wants to be my friend. Pet stores are all businesses, too. Just approach them as you should any business, as an educated consumer. -Steven Pro>

Stocking "cleaning crews" (hermits, snails), lighting coral help on WWM
Bob,
Thanks for the reply. I've read the WWM sections about inverts and the quantity, and also noticed that you're not such a fan of these cleaners.
<Yes>
To be more specific, I have 20 blue leg hermits, 10 red leg hermits, 3 margarita snails, 8 Cerith snails, 5 Astrea snails, 1 peppermint shrimp, 1 cleaner shrimp, 1 serpent star fish (only 4-5"). Can you give me your insight on why you don't agree with so many inverts?
<In a small volume (your 24 gal. cube in this case) the hermits often "cross the line" between being scavengers to predating desirable organisms... including each other... The snails die, en masse sometimes... and their dissolving takes most everything with them...>
I read somewhere that this many inverts was the perfect amount to keep an almost maintenance free tank for a 24 gallon tank. Were they just full of B.S. so that they can sell their product?
<Mmm, well.... there is at least a "difference of opinions" here... there definitely are a bunch of "pro" cleaner uppers as well as "cons"... Each must decide for themselves... but if you take a look in the wild, you will see there are few parts of natural reefs so arrayed>
Also, currently I don't have any corals, how many hours should the lights be on? And how many hours if I do get corals? Thanks. Perry
<Please put the terms: "lighting corals" in the Google search tool here: http://www.wetwebmedia.com/  Bob Fenner> 

Clean Up Crew For Overstocked Conditions - 02/10/06
I have a 46 gallon bowfront aquarium that I have had set up for 8 months now.  I am wanting to add some sort of clean-up crew to help me with keeping this system as healthy for my fish as possible.  I have done a lot of research as far as what's compatible with my other fish (a 4-inch Niger trigger, a 9-inch snowflake eel, and a 5-inch emperor angel).
<<Ack!!  Too much  fish flesh for this tank my friend!>>
I know this is too small of an aquarium for these fish and I'm planning on getting one twice this size around April.
<<Mmm, may do for a year or so...really need one twice again that size for this mix.>>
I am constantly getting these algae bloom, mostly red and green and some brown,
<<Likely due to the "overstocked" condition of the tank.>>
in my tank so I was wanting to get something to control it.
<<Better to address the cause...>>
I recently went to my LFS and I purchased 8 blue hermits and 3 Mexican turbo snails and introduced them to my tank without any problems.  Everybody's getting along without any disputes.  I was told by my LFS that I should get 7 or 8 more hermits and a 5 more snails... is that to much in a tank my size?
<<You might get by with the addition of the hermits, though the Snowflake moray may take notice of them eventually and thin their numbers...but I wouldn't add any more of the Mexican Turbos to this size tank...if that's truly what they are.>>
I want to get some sort of sand sifter as well so I wanted to know what you recommend.
<<Do a Google search on sand-sifting gobies.>>  
Can you think of any other invertebrates that would be beneficial to my tank and be able to survive the other fish in my tank?
<<Hmm, nope...not under these circumstances.>>
Thanks for your help!
Brian Brantley
<<Regards, EricR>>