These days, a pretty good number of aquarists (a majority of them, perhaps) prefer bare-bottom tanks. Bare, as in, no sand or gravel on the tank floor. Just as these folks opt for bare-bottom display tanks, they opt for bare-bottom refugia. The basis of this trend is a fear of detritus–specifically, that substrates attract and accumulate detritus. Now, detritus does kind of suck, as it looks gross and stores nutrients that can (as they are released) contribute to unwanted algal growth. At least in theory, if you don’t have a substrate, particulate organic matter cannot easily get trapped on the bottom, and so your tank will be cleaner.
This all deserves a closer look. And some deeper thought.
Sand Stirrers and the limits of mechanical filtration
In bare-bottom tanks, just as in tanks with a substrate, detritus is eventually mineralized (broken down) into excess nutrients and dissolved organic waste. “No problem,” the bare-bottom proponent might say, “I’ll just go heavy on the mechanical filtration.” Fair enough, so long as mechanical filter media are thoroughly rinsed on a regular basis (i.e. daily), very little of entrapped particulate organics can mineralize much. Effective means of nutrient export, right?
Yes and no. Consider first of all that mechanical filtration is indiscriminate. It removes all particles down to some particular size–both bad and good. This means that in addition to all that rinsing, you’ll also have to mess with it (i.e. remove it or somehow divert flow around it) whenever you feed. Otherwise, all of those pricey fish foods and coral foods you add will almost instantly become “waste.” Top-dollar detritus.
But an even bigger concern about aggressive mechanical filtration is pod mortality. Think about it… A coarse mechanical filter medium that cannot strain particles of less than, say, 75 microns is pretty much worthless. Yet, finer media that strain anything smaller than 75 microns will remove most adult copepods and even many copepod nauplii. They’ll be harder yet on larger pods like amphipods. No, we’re not saying that mechanical filtration outright decimates an entire pod population. Nor do we claim that pods simple perish upon first contact with a mechanical filter medium.
What we are saying is that fine mechanical filtration does trap some (and potentially a lot of) pods and therefore limits their population size. Really “good” mechanical filters can completely eliminate copepod species that undergo a pelagic adult life stage. See the vicious circle here? You keep a bare-bottom tank to enhance the collection of detritus in your mechanical filter, which you install because you have a bare-bottom tank–to the detriment of copepods, which are your best weapon against detritus in the first place!
At this point, we present an alternative (and dare we say more natural?) approach; keeping a substrate, using only super-coarse mechanical filtration (if any) and promoting the degradation of detritus by detritivores such as (but not limited to) copepods.
The hitch? You need a crew of so-called sand-stirring organisms. Stirrers accomplish two important tasks. Firstly, their excavations encourage the release of organic matter from deep within the substrate. These wastes are otherwise inaccessible to detritivorous animals not just because of layer of sand above them, but also because they may be situated in anoxic areas. This leads to the second job, which is aerating the substrate surface, thereby increasing the depth at which aerobic detritivores can safely forage.
Substrates=Reef food factories
There is a very large diversity of detritivorous reef critters. As one might expect, many of these sediment-dwellers are tiny. The little guys include microcrustaceans such as harpacticoid copepods, cerith snails, various worms, etc. There are many larger detritivores as well. These range from sand-sifting gobies to sand-sifting sea cucumbers.
It almost all of these cases, the creatures are not really eating the detritus to eat the detritus; rather, they are going after the rich microfauna that is associated with the detritus (bacteria, fungi, protozoa, etc.). The smallest detritivores just crawl around within the sand and gobble up teeny particles as they find them. Larger ones, however, swallow up big mouthfuls of sand, detritus and all. They then either strain out the goodies and spit the sand back out, or they actually eat the sand, digest the goodies, and then poop the sand. The evidence of this latter group is sometimes observed over the sand bed surface every morning in the form of distinct formed, clean, white sandy pellets.
Not all sand stirrers are detritivores and not all detritivores are sand stirrers. For example, certain fish (e.g. jawfish) and certain shrimp (e.g. pistol shrimp) build elaborate borrows. These burrows help aerate deeper parts of the sand bed through irrigation (that is, movement and exchange of waters between the top and bottom portions of the burrow). This allows other creatures (especially detritivores) to forage deeper in the immediate area, and so compliments and promotes the activities of sand stirrers.
Some creatures help to keep the sand bed clean even without doing any stirring. These range from pods to detritivorous fish (e.g. court jester blennies). The reason is pretty simple: Where detritus is consumed at the substrate surface, less detritus can settle deep within the substrate.
Basically, having a large and diverse clean-up crew and a diverse team of sand stirrers can significantly reduce the need for mechanical filtration, if not eliminate the need altogether. Some creatures will fill just one of these roles, and others will fill both. What’s important is that the aquarist assembles an ecological community that breaks down detritus as quickly and thoroughly as possible–the widest size particle range, the most types, in all locations of the system. This encourages rapid recycling, which encourages large populations of both zooplankton and bacterioplankton, which are both important components of the coral diet.
ryorzins says
I would get a diamond goby but my substrate is CaribSea Hawaiian, black. It is not a fine powdery sand. Not sure if the diamond goby can handle sifting my sand.
billy.t.williams12 says
That is sad to hear, Diamond Gobies are some of my favorite fish. Sounds like you need a new tank and new sand! lol
Tyler says
Definitely need to get one of these guys for my tank
Raven says
would loaches be part of the fish you would not use subratie with and nice article
ernie.alvarez0325 says
I love
My diamond goby! Always digging up the sand and keeping the bottom clean!
Wayne Zenecke says
I like my conches
JohnR says
Years back I tried a sandless tank and I noticed that my fish were not free swimming lime some of my other tanks. After a few months, I added sand to it and the next day everyone was happy swimming about. Only thing I can think of is that they were seeing an obis below them and were staying in the rocks for safety. I keep a good mix of stirrer in my tank now. Yes, they do like to pile the sand in different locations throughout the tank, and I have to redistribute when I clean it on the weekends, but it keeps things interesting.
Samantha Obergas says
Thank you for sharing your experience—it’s always interesting to hear how different setups impact fish behavior! Your observation about the fish being less active in a sandless tank is really intriguing. It’s possible that the absence of a sandy substrate created a visual effect that made the fish feel more vulnerable, as you mentioned. Fish often use visual cues from their environment for comfort and safety, so adding sand likely gave them that sense of security they were missing.
I’m glad to hear you now have a good mix of sand stirrers in your current tank. As you noted, they do tend to pile the sand in certain areas, which is all part of their natural behavior, but it’s great that you’re keeping them happy and engaged in their environment. It can certainly keep things dynamic and, as you pointed out, adds some variety to your routine when maintaining the tank.
Thanks again for the comment, and happy reefing!
James A Cabeceiras says
Hello, my daughter’s reef tank has the same Hawaiian black and it does have a lot of powdery dust in it. What I did was put a bristle worm trap in my tank and caught about 30 worms to sift her sand and they are doing a great job along with our watchman gobies!
crplcarott says
I had a Diamond goby and the same substrate. It handled it with no problem. Just make sure you have a good top on your aquarium because they are escape artists.
crplcarott says
I had a Diamond goby and the same substrate. It handled it with no problem. Just make sure you have a good top on your aquarium because they are escape artists.
Eric Richardson says
good info
Fawn Curtis says
Try Tongan sand sifting snails. They are striking for sand sifters and do a great job.
ryorzins says
Might have to get a Diamond Goby.
dgbsmb says
I love my Diamond goby, he sifts my sand from one to the other of my 300 gallon reef tank, constantly turning my sand
Ricks Garage says
I love the little critters that live in the sanded and come out at night
Jimmy Kok says
sand provides a good home for many beneficial creatures
Botzz28 says
Now that I am populating my tank with eco pods can I keep the more hard to keep starfish other than a regular sand sifting star ?
Brian Veach says
I’ve seen such an improvement in my tank when I focused on keeping the sand clean. We’ve added starfish, crabs, snails, hermits, and sifting fish all with the intention of improving our sand. When we did that, the coral exploded! The benefits have been clear.
tonymutti says
Gobies and snails like Cerith are great. I generally stay away from sand sifting stars because they each a lot of the microfauna.
Eric says
I’ve always had some type of ? stirring or sifting creature in my tanks since 2004. My by far favorite is a pistol shrimp with a Goby, no matter the species!
b_burnett90 says
Got me a diamond goby and conches
sfinnell says
I love my pistol shrimp sharing its home with my goby pair, but the bigger that he grows, the more sand that he constantly moves. He collects it near and far in my tank and as a result disturbs a lot of corals and rock with his never-ending construction. Now, I don’t know if I love him so much! He definitely cleans the sand!!
Eric says
I’ve always had some type of ? stirring or sifting creature in my tanks since 2004. My by far favorite is a pistol shrimp with a Goby, no matter the species!
Ed says
Need more cleaner crew since my Dracula goby jumped into the overflow and past the UV sterilizer.
matthew.k.wyatt says
Awesome read!
debken890 says
Great post. Love my CUC including diamond goby always cleaning sand. Would never go bare bottom doesn’t look natural
jhoffman says
Very interesting read.
pkrinsky says
Sand is its own biome
pkrinsky says
Sand is its own biome
pkrinsky says
Sand is its own biome
bundler says
We love our Goby pair!
vosrichie says
Cleaners, and food. Good combo
vosrichie says
Cleaners, and food. Good combo
Victoria says
Sand critters are so much fun.
Robert Sherwin says
Clean up crew I’ll take two
Leroy Lewis says
If you have sand in your aquarium it is easy to find something you like to watch.
kweisen-1082 says
I need a goby or 2.
Alex Merida says
I have a pink spotted goby and some nassarius snails.
Thanks for the awesome information #Algaebarn
Odo Dietel says
I need some
cmykredesign says
I use to have a Tiger jaw fish he used little shells to make his house and would throw crabs who got inside his house
Stella says
Cuties
anatolek says
The macro world is very interesting to watch!
Tiffany Hook says
Wow interesting ?
Tiffany Hook says
Wow interesting ?
vegasv128 says
I don’t think sand gobies like my chunky black sand.
jhoffman says
Very interesting read. Some pretty neat creatures.
Cassondra Cunningham says
My goby creates valleys and mountains all in my tank with the sand.
chief300 says
I like sand shifters, but I can’t seem to keep them alive.
Isaac Guenther says
Goby is next fish goal.
sam says
how about keeping substrate in the sump?
ply5757 says
very interesting reading this article.
Jim says
Good info
Dallas T. says
I need more copepods!
robncasey says
Glad we have a new order of pods from Algae Barn! Can’t wait for them to arrive! ♥
Michael says
Awsome!!@
tbrown3589 says
My Hector’s stirs some, but I definitely need another. I’m thinking a couple of conches.
brittneymlasley says
Defiantly need to increase my copepod count!
Rex Camerino says
Woohoo
alenm826 says
What better then to see a sandy snow shower in your tank daily gotta love the goby.
sharkbaitsnyder says
Very read!
sharkbaitsnyder says
Very read!
James Bradshaw says
I’ve always been a fan of sand so conches are an absolute must for me. Besides being an abnormal creature in my tank that gets oohs and ahhs from guests but they are the best sand stirrers I’ve ever had. With the combination of monthly subscriptions of pods from algae barn, my water changes are every few months max.
gerrynator4 says
I have a tiger sand conch, he’s great at sand-sifting, and is funny looking
gerrynator4 says
I have a tiger sand conch, he’s great at sand-sifting, and is funny looking
Beth S says
My favorite was my horseshoe crab. Fun to see when he periodically resurfaces
Alexandra Gulledge says
I really want a sandshifting goby.
cayenne9479 says
great article
CHRIS GODFREY says
Tiger conch are great. Love those
Robert Benedict says
That is a great article. I am always adding new and different things to my tank to help keep it clean.
rabenedict2 says
Great article. I am always adding new detritivores to my tank to help keep it clean!
Alan Biddle says
I have been thinking of trying running without mechanical filtration. Helpful article.
danielstrahan.11 says
A variety of sand sifters is a must in all my tanks
Rick says
Gobies are one of my favorite fish
jason_lifted35 says
Need to get a tiger sand conch, love my diamond watchman goby.
Jacob Carpenter says
They remind me of the fish from SpongeBob with the pizza
Aaron Prince says
Great info
alb2 says
I’ve been fond of the fighting conch myself.
teresaannehand says
nice
Peter says
Gobies are awesome.
drcjperry16 says
I need a diamond goby
chrisddavis79 says
Stirring things up
Jeff Carr says
Gobies are good, but I have a nano so adding another fish won’t help much. I think I will focus on other CUC types like… pods!
Jeff Carr says
Gobies are good, but I have a nano so adding another fish won’t help much. I think I will focus on other CUC types like… pods!
rocco.paul says
Interesting article.
Wendy says
Live making my gobie happy! Great read
chrisddavis79 says
Starfish for me please!
George S says
Very cool
deltaechosix says
Love our diamond goby!!
kevin.t1680 says
Might have to get a Diamond Goby.
Angel L Bunch says
Very cool!
Cristobal Barraza says
Nice info thanks
b_burnett90 says
Love my diamond goby and conch
tkshaffer70 says
Cannot say enough about the yellow-headed sand goby. In my experience they will eat any and every prepared food provided and still spend all day turning over the sand bed. Very attractive as well. Just be aware they will climb up in the water column as expelling the sand. Nice article…very informative!
patscheuplein says
I have 2 harbour gobies. They sift sand so much that I have move it back.
gmale789 says
?
titanicwilliam says
I love my diamond Goby
Brad Martin says
I got some pods and am looking to get a goby to help ster sand around.
Brad Martin says
I got some pods and am looking to get a goby to help ster sand around.
Brad Martin says
I got some pods and am looking to get a goby to help ster sand around.
Brad Martin says
I got some pods and am looking to get a goby to help ster sand around.
sarah.sandpoint says
I wonder if I could get some sand sifting gobies when we have a pretty established blenny, he seems okay with all the other fishes – would love to add some gobies, they are pretty cool!
Jonathan Morera says
Sand Sifting Starfishes are my go to!
blackadonai says
I already have a diamond goby. He sure moves a lot of sand around. Unfortunately I’m having a cyano outbreak and he won’t touch any of the sand with cyano on it. I also have a sand conch and a tiger tail cucumber that I only see occasionally. I’d also really like to get a couple of those court jester blennies
bmxxmikexx says
cool!
bmxxmikexx says
super cool!
Jessica Ramirez says
Interesting
Jessica Ramirez says
Interesting
whittaker217 says
I always do a monthly restock on my cope pods
mariahdavila says
Great blog wonderful info. I’ve been trying to get my little paws on a diamond goby. One day!
Chris Briggs says
I have a diamond goby in all my tanks!
Brandon says
I’ve always loved having a diamond goby. It’s so fun to watch them gobble sand. Such a cool fish. I need to upgrade my nano so I can have one again.
Will says
Gobies are good, except I’ve had bad luck with them jumping out of the tank..
shawntolman13 says
I am just setting up a 155g with DSB.. definitely have the sand stirrers!
sourdog22 says
Interesting read
cranescoop says
Very interesting ideas!
Kathleen Ryan says
I need more sand stirrers. Thanks for the ideas.
ernie.alvarez0325 says
Love my diamond goby. Keeps sand nice and clean!
Daniel Olguin says
My dimond goby keep my sand clean
Mark's fish tank says
Been trying to find a goby
billandambermags says
Turkey baster
billandambermags says
Turkey baster
billandambermags says
Sand is my nightmare right now.
Dan Russell Zabler says
Never had a diamond goby but I had a watchman goby with a piston shrimp. They always kept my sand nice and white.
markwdunlap88 says
I loved my goby until he became daring and decided to go skydiving during feeding time… didn’t catch him in time. Haven’t tried another yet
mybuddykosar says
Good info
Gr says
love my nassarius
schmidtcaters says
One of my constant struggles is keeping enough. And maybe the right balance of sand stirrers in the tank. Keeping pods alive is a huge focus for me as I have a dragonette.
Menezes Industries says
i have a yellow watchman goby
joshuastevens930 says
I love my diamond coby
Andrea says
My diamond goby remodels my tank allll the time! Also, if I put a coral on the sand bed, he often says nope and moves it – usually hidden where it is hard to find it. He is a funny little guy, but he keeps my sand very clean…. with lots of mountains.
grammy6851 says
Destroy the detritus
sclarke_o says
I want a jaw fish but I currently run bare bottom … I’m going to switch I just don’t know when ….. sand stirrers are fun to watch seen them in the wild on a dive!!!
paulmatthewguilliam says
Very interesting read.
Matt Armstrong says
??
dengwilliam96 says
I got my pearljawfish Aii How
tcobosco says
My black and white Clowns do a great job keeping their acre on the reef very stirred up lol
robert.lowell says
Interesting
chad.boehler says
Interesting read.
Alan J. Tomasetti says
I’d love to have one, though hopefully it doesn’t burry the corals in the sand too much!
Christopher Hooks says
This is a must to have in the reef tank
trizzi says
Love them
Kevin says
Definitely need to get a diamond gobby
kingmahen says
I can’t have any Gobies because they would bury my sand Ed corals like my Scolys, Trachy’s and Lobos
kingmahen says
I can’t have any Gobies because they would bury my sand Ed corals like my Scolys, Trachy’s and Lobos
Rob says
Gotta stir that sand!
Christopher Johnson says
I need me a sandsifting starfish
Christopher Johnson says
Shake it up like a salt shaker
Stacy H says
So many interesting creatures in saltwater!
Austin Clark says
Looking forward to adding my diamond goby. Just making sure he will have enough copepods to be big and healthy.
Kelly Davis says
I love my pink spotted watchman goby! They don’t usually sift but mine does. Also tries to be an escape artist when given the chance.
KiltedReefer says
Someday I hope to get my diamond goby and have him create his mess in the sand. Need to increase copepod levels first.
scott says
WoW
Kass says
Ready to get my tank started and add some of these little work horses.
Yueqi Wang says
Good blogs!
Scott Allan says
Only room for one ss-fish… now which one?
Joel says
need some pods
Montana Morrell says
Gobies
eric says
Heard sand stars actually harm your substrate by taking away all the beneficial stuff
jackbauer24.1 says
Why haven’t there been any winners since the first of October ?
Pete Tellers says
Good article! Thank you…
blindfish21melon says
Love it!
zdunbar8515 says
I really enjoyed reading this !
Andrew says
I would love a sand sifting sea star, but with my tank only 6 months old I don’t want to risk him starving to death.
chriscatherman says
I have a Diamond goby & a conch they keep my sand bed looking beautiful!!!
Marijane Stevens says
It doesn’t feel like a reef tank unless you have a sea star.
joshaz85203 says
Amazing star fish does my tank well
Tim T says
I would like one in my tank.
Dustin says
Need one
Dustin says
Star fish
Mason says
Nice
Cary says
My Diamond Goby is great
Christian Mandilawi says
I love my sand sifter
Carlos Matias-Tejada says
me too. until it ran out of food and melted on me. i would target feed it and nothing!!
Menerd The Menace says
I need these in my life
Eddie Fleetwood says
My Tiger Pistol Shrimp does love moving sand
Kelly Pinckard-Hazzard says
Love the sand sifting stars and love your articles!
CORY SANCECIZ says
Good read
Leon Henson says
Need One
Leon Henson says
I Need One
Premchander Reddy says
Ordered some already
globalfisher says
Great post! I have had a few gobies before and really enjoyed them.
Jeremy says
I have a yellow watchman with a pistol shrimp, but she’s not the most active.
Joshua Valladolid says
Super important to stir your sand naturally.
Barry Roper says
Looks like a sand-sifting gobie may be my next purchase…
joshua ramos says
Nice
Noah Fowler says
The sand is a whole different world I bought a microscope to see all the microscopic live living there. It’s amazing
Leyla O'Connor says
My goby covers my corals! UGH!!
janelle says
I heard sand sifting starfish can annihilate the organisms in the sand in an incredibly short amount of time
james haygood says
Nice asset of the system
RYAN LEE SMITH says
always a good read, far to many of us underestimate our sand beds.
Josh says
Love them gobies
Nicholas Aguiar says
interesting starfish, it blends well with the tank but not too colorful to take away from the centerpieces, especially in small tanks. i’d definitely get one for my current tank.
Josh says
All my gobie does is aggravate my corals!!
Gordin says
Sand Stirrers and Detritivores are NEAT
Glen McLaughlin says
Useful information
Sean says
I have a Diamond Goby very unique fish!
Jeffrey Miller says
Always liked a sand bed and I will probably always stick to it.
Channon says
I love my sand sifters copepods to the rescue
professorcanswanky says
I’ve got a diamond watchman and two tiger conchs in my 57 gallon and they keep my sand bed spotless!
Noah Fowler says
Very underrated live stock for your tank I always have multiple species that will move thru the sand
Travis Callaway says
Half the time I forgot I even have one
Amber Breedlove says
I CANNOT WAIT until i get more little critters in my tank
Brendan says
I have a diamond goby, and I could see the impact he had on the sand bad quite quickly.
Lisa Riggio says
luv dem gobies
Ryan Oneil says
Have 1 and love it
Curtis D Williams says
Good to know
Trevor Humphrey says
Great stuff
Brent Grandidier says
Diamond goby is next
Shawn says
come on free pods
Matthew Hubble says
I have two gold headed sleeper gobies and they are amazing at sand sifting…. And spitting sand all. Over the rocks lol they also have their home came decorated with empty shells haha
Tyler Firu says
really good information crazy
Weston Zach says
I like Tiger and /or fighting conchs
Serjay says
I have one Gobi
Serjay says
I have watchmen gobies
Serjay says
I have two clownfish might get gobies this week
DeAndre Cain says
I would name it Patrick
Joseph Uttlinger says
Don’t have a sand sifter yet, but it’s definitely on my list.
Kristen says
my clowns and Gobie get along very well
Michelle Collins says
Ok
Peter Stephens says
Stars work for stirring sand bed
Lacy Croft says
Need some gobies
Tyler Twigg says
I got a golden heads leper goby 2 conches 2 saft sifting stars a engineer goby and a sea cucumber to keep my sand clean
Tyler Twigg says
I got a golden heads leper goby 2 conches 2 saft sifting stars a engineer goby and a sea cucumber to keep my sand clean
dapettit516 says
I found information easy to read and understand.