Live Sand

What is live Sand and how can it be alive?

Well, the sand itself of course is not alive, but there are organisms they are alive that are around the live sand and within the live sand or on top of the live sand, and most these organisms are beneficial and help to maintain a balanced aquarium. So live sand can be very important in maintaining a healthy reef aquarium, but it does have its drawbacks.

There are two important considerations when you’re dealing with live sand.

The first consideration is particle size and second is the composition of the sand.

Particle Size

Particle size is probably the most important, because most organisms don’t care or even know what the composition of the sand is. They just want the correct particle size. If the sand particle sizes are too large, there will be large voids between the particles and it’s going to trap detritus which will eventually feed hair algae.

Many organisms may not survive I have found if this size of the sand particle is too small. The sand becomes compacted and almost dirt like and there’s little room for organisms to move between the sand particles. Oxygen may also be limited because gaseous exchange is inhibited.

Best Particle Size

So what is the best particle size for live sand?

In general, we recommend that you buy live sand that is what we call the “sugar fine” in size. Sugar fine means the granules of sand, that is, the particles of sand are approximately the size of grains of sugar. This size is a nice compromise between too large and too small. If the particle sizes are too small, they compact easily. Then they create a barrier through which organisms and oxygen cannot get through.

Sand Composition (what it’s made of)

The two commonest choices of sand are regular playground sand (Silicon dioxide) or Aragonite (calcium carbonate).

Many people don’t recommend using playground sand because they say that it releases silicates into their system, causing the growth of unwanted diatoms (brown slime on the glass).

I have not found this to be the case in some systems. When I use regular playground sand I purchase it from swimming pool shops or your local hardware. However this is only used when I set up large systems.

However, due to the large systems and possibly the amount of sand we use compared to the huge volume of water this may be small enough to for the system to absorb any silicate that maybe there. Consider it if you have a huge tank. But if you have a smaller tank, it’s probably safer to buy the aragonite.

We like the play sand because the particle size is close to the sugar fine sand that we recommend, and it’s cheap. The organisms that live in it don’t know if its play sand (silicon dioxide) or if it’s aragonite (calcium carbonate).

Don’t worry about the higher pH typical in reef aquariums, it seems like the buffering of the sand is fairly minimal and insignificant, especially if you’re planning on buffering from other means such as calcium reactor or a two-part solution. So I wouldn’t make my sand choice based upon that. Some papers have indicated that the pH in the sand bed is so low (acidic) that you don’t get significant dissolution of the calcium carbonate particles to help with buffering.

So what is the benefit of a live Sand bed?

A live sand bed provides the housing, or structure, where bacteria and small organisms can live in order to break down the waste products of your aquarium.

We know how large the sand should be, how deep should the sand bed be?

Your sand bed can be either thick of or thin depending upon what you’re trying to accomplish. We actually recommend that in the aquarium itself, that you maintain only a very thin layer, for aesthetic purposes only.

I don’t recommend that you have a biologically functioning sand bed in your aquarium as this can cause some problems when the tank gets older. It is much easier to work with, if you have just a very thin layer of sand on the bottom glass of your aquarium, so that you don’t see the bottom glass. Anything more than this will require regular maintenance and can lead to an eventual hair algae problem.

We recommend that you maintain a sand filter outside of the main aquarium in a sump. Sumps are great places, because here if you do have a sand bed problem, you can disconnect it from the system and not disturb your main aquarium. You won’t have to dismantle the live rock and corals in the aquarium to redo the sand bed.

In the sand bed, it’s very important to have something working through the sand on a regular basis. Otherwise the sand will clump up and harden and become ineffective. Many sand sifting organisms such as cucumbers, stars, and certain fish will move the sand around and keep it loose. We keep quite a few horseshoe crabs in ours and they do a great job of stirring up the sand.