A Cursory look at Live Sand, It’s Clean Up Crew and It’s Importance.

​by Charles Steinfeld 

Photo by Lorenzo White                                                                                                                                                          Pod Picture by Chad Clayton of Reef Nutrition

​Similar to Live Rock, Live Sand is a surface for bacterial populations to grow on and break down organics.  Think of your live sand as being home to millions of bacteria as well as macro organisms (like amphipods and copepods) that will benefit your ecosystem at every rung of the food chain.  There can be serious implications though if you have either too little or too much, I know, too much of a good thing can be a bad thing.  The live sand houses many different species of bacteria and as such if the depth of your sand is at the in-between depth you may be doing yourself a disservice.  I personally use the “under 2” or over 4”” depth rule.  As in I don’t like for my sand bed to be between 2 and 4”.  This is simply because the compounds that are broken down between these depths can result in compounds that are worse for your tank than are beneficial.

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Photo by Ernest Mcelwee

Photo Credit : Laura Liyanage (starfish), Marvin Ballard (Sea cucumber), Lori Johnson (Hermit Crab, Conch) 

​A quick list includes:

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1.  Nassarius sp. snails - Although these guys are great detritivores (some are also carnivorous so make sure that you get the correct species) they simply live in the sand. They do nothing to process the sand bed but their constant movement through the sand bed keeps it aerated and they are detritivores that will help to consume left over food. These guys are the ones that look like storm troopers coming out of the sand.
2.  Sand Sifting Starfish – These guys are great for large aquariums but oftentimes don’t live long in captivity because they exhaust their food sources and slowly wither away. I typically don’t suggest these for any aquarium under 75 gallons or a 4’ by 2’ footprint with ample sand resources. These stars will move throughout the sand bed and keep it aerated while eating detritus and bacteria.
3. Sand Sifting Gobys – Similar to the Sand-Sifting Starfish they tend to exhaust their food sources pretty quickly if they don’t eat prepared foods. They also don’t typically adjust to eating prepared foods meaning that once they exhaust their food source, they slowly wither away. These goby’s can also be destructive to your reef as they hover above the sand bed and are known to deposit sand at almost all levels of the reef. They scoop a bunch of sand into their large square shaped mouths and sift it through their gill cavities. They are indiscriminate on where this sand is dropped leading to corals being covered in sand (something that the corals don’t really like!). They can also pick rocks or small corals up off of the sand bed and move them around into burrows or into places where you just can’t find them, leading to potential mortality. I suggest these for large aquariums (over 100 gallons) with ample sandbed resources and in aquariums that do not have a lot of small corals on or near the sandbed.
4. Hermit Crabs and Snails – These guys don’t usually go into the sand bed but they do a good job eating detritus that falls onto the sand bed. C. tricolor or Blue Leg Hermit Crabs are great detritivores and are also extremely hardy (although short lived ~1-2 years max lifespan usually). I am a huge fan of diversity in your animal population, I personally prefer a couple of many species rather than a lot of a few species. At one point in my current tank I had 10 species of cleanup crew, needless to say their population kept my tank pretty spotless!
5.  Sand Sifting Cucumbers are my favorite for several reasons including their ability to self-replicate, process large amounts of sand and their tendency to be nocturnal. This means that although they are ugly, you don’t have to see them to see their results. There are several species of these that are regularly collected for the aquarium hobby and they are generally inexpensive (<$10). Think of these guys as little sand processing factories with dirty sand going in one side and clean sand coming out of the other. For the most part the species that process sand the best are pretty ugly, but it’s what’s on the inside that counts! Look for Holothuria sp. Cucumbers.

Sand bed health is incredibly important for your aquarium, it’s also what can set your aquarium apart.  A clean crisp white sand bed can make your tank look spectacular, a dirty sand bed can make your aquarium appear dirtier than it really is and draws attention away from the other animals in your Aquarium, no one wants a dirty floor to take away from beautiful art on the walls, why would you allow a dirty sand bed to draw attention away from your reefs?!

Honorable Mentions. 

Photo by Marvin Ballard