Since sand is a large part of your tank's aesthetic, we always like to advise you to choose sand that looks good to you. Having said that, you will first choose whether or not you want to use live or dry sand. After that, you should make your final choice based on grain size and color, both of which will affect the overall aesthetic and function of the sand in your reef tank.   

Calculate how much sand you need using our Sand Bed Calculator.

Live or Dry Sand? 

Live sand is alive with beneficial bacteria that will help initiate or seed the nitrogen cycle in your display aquarium.  It is packaged wet, has a low dust/sediment content and is designed to be poured directly into your display without any sort of rinsing or pretreatment required. Within the Caribsea live sand options, you have the "Oceans Direct" which is collected directly from the ocean and contains the natural biodiversity that comes along with it, and the "Araga-Alive" which is dry sand that is then combined with water that contains live beneficial bacteria before it is packaged. 

Dry sand is exactly that, it is packaged dry and does not contain any living bacteria. It is typically more affordable but requires a little extra work. Most dry sands should be rinsed prior to use in your display to help reduce the dust/sediment content. To learn more about using dry sand and how to rinse it, check out our video "Why Choose Dry Sand for Your Saltwater Aquarium Sand Bed?".

Caribsea Aragalive Sand Grain Size

Grain Size

The grain size or particle size is important for two reasons beyond the aesthetic. For starters, there are some animals that prefer larger or smaller grain size sand so be sure your researching appropriately. For example, many Wrasse species should have small-medium grain sand beds to burrow into at night. Jawfish will benefit from medium-grade sand with larger crushed coral pieces and shells mixed in to create a burrow as they would naturally. Sand sifting gobies and inverts should have smaller grain sand to ensure they can successfully sift and find food amongst the sand.  

The second reason is water flow. In reef tanks, we create strong currents to mimic what corals and other reef animals would experience naturally.  This strong flow benefits the tank in many ways but also can stir up and move around your send particles should you use a grain size that is too small. Small grain size sand (Sugar-size" or "Oolitic") is often a real pain when used in your typical mixed, LPS or SPS dominate style reef tank where adequate internal water flow is critical for the health of the corals.

Caribsea is the leading manufacturer of sand used in saltwater aquariums and provides grain size measured in millimeters. Being sand is natural, the bags will often contain a mix of different sizes but are sifted during packaging using a maximum to ensure you're not getting anything larger than what you desire.  

  • Small Grain Size: 0.0mm - 1.0mm
  • Medium Grain Size - 1.0mm - 3.0mm
  • Large Grain Size - 3.0mm - 5.0+mm

All things considered, a majority of hobbyists choose a medium grain size like Caribsea Special Grade (1.0 - 2.0mm) because it is small enough to look very natural but will also stay put in most reef tank flow conditions. It is also suitable for most all wrasses, gobies, and many of the sand-sifting inverts we rely on to keep the tank clean. It's the best of both worlds, is very uniform in grain size, and tends to work out great no matter what kind of tank you end up with.

Caribsea Aragonite and Ocean Direct Sand


Most reef tank owners opt for very natural-looking sand in some shade of white or beige. There are also black varieties and various mixes that will contain a majority of your natural white sand with black or pink particles mixed in.  You can also get brilliant colored sand options like neon green and hot pink but for the most part, you won't find this kind of sand in modern reef tanks.  It tends to take away from the ultimate goal of creating a natural-looking reef.  

Natural white is best because not only does it look nice and compliments the colors of your fish and coral, but it also tends to mask debris or detritus very well. Pure black sand may seem attractive to some but consider this, black sand will not easily mask detritus and may have magnetic properties. That means it tends to look dirty almost right away and can also attach to your magnet cleaner causing you to scratch the tank walls. The contrast the dark sand creates can be attractive, its just not all that practical. 

Top Performers

Now that you understand how to wisely choose the best sand for YOUR tank.  Let's take a look at some of the top performers in various categories across the board.  

How Much Sand Do I Need?

We recommend most modern reef tank owners use no more than 1-2 inches of sand unless you have some special animal that requires a deeper sand bed like Garden Eels or Jaw Fish.  Deeper sand beds can be tough to keep clean and will trap detritus, making your life harder in the long run.

Calculate how much sand you need using our Sand Bed Calculator.

Keep in mind, finer grain sand will often require more weight to achieve the same depth. We have some great charts in the product descriptions of our sand options that give you an idea of how much sand you will need based on tank size. There are also sand bed calculators available on the internet that make it easy, just enter your tank dimensions, select the desired sand type and depth, the calculator will produce how much you need to buy.