
Live sand for saltwater aquariums is like live rock. It contains beneficial bacteria that breaks down organics in your reef tank. Live rock is a more effective and doing this job and sand has started to become more just for looks than anything else. Some reefers prefer to not even have sand and go with a bare bottom tank. I personally prefer the look of sand versus a bare bottom tank but I’ve given it a long hard thought. I may go with one in the future but I haven’t done so yet.
Remember, the finer the grain size the more likely it will get blown around your tank. Finer grain sands tend to look better and are great for sand sifting fish but you’ll need to either adjust flow or deepen your sand bed if you want to avoid bare spots.
In the not too distant past it was very common for reefers to have deep sand beds in their aquariums. The logic behind this was to create a low oxygen zone for bacteria to live forcing the bacteria to strip Nitrate of it’s Oxygen molecule and releasing the byproduct as nitrogen gas. Unfortunately any sand in your reef tank will eventually accumulate detritus that will need to be cleaned out before it begins generating the unwanted byproducts of the decomposition process. While many do still utilize deep sand beds, there really are better ways to control nitrate and phosphate. Live rock is the primary replacement. Reactors, refugiums, algae scrubbers, protein skimmers, and bio media are all additional methods of dealing with left over fish food and fish waste.
Bare bottom tanks are becoming popular since they make maintaining your aquarium much easier. There’s no way around having to clean a sand bed on occasion. Without the sand bed fish waste and excess food break down into the water column prior to decomposition and are largely removed by a protein skimmer. I’m all for simplifying tank maintenance but I’m personally not sure I can go all in on a bare bottom just yet.
One of the great things about live sand is that it’s great for jump starting your aquarium if you’re starting with dead rock. We’re not going to dive into cycling a new tank in this article but live sand contains the same beneficial bacteria that live rock does. You’re not going to get hitchhikers from live sand and the bacteria can migrate to your rock quickly. There isn’t much cost difference between dry and live sand so there isn’t a reason to not use it if you’re going to use some kind of sand in your aquarium
Be sure not to discard the liquid that came with your live sand and keep an eye out for additional packets of clarifiers you can add to your tank that are often included.
Aragonite and crushed coral are generally pretty similar except aragonite is typically a fine to medium sand and crushed coral is pretty large. Both contain calcium carbonate which can be good for coral growth. Black sand typically doesn’t contain calcium carbonate. Many corals need calcium to grow and it’s possible that calcium from your sand bed can be a source but if that’s true it certainly shouldn’t be the main source of calcium. Dosing kalkwasser or using a calcium reactor is way more effective. Choose your sand for it’s aesthetics and not for it’s calcium content.
The general rule of thumb is 10 pounds of sand covers 1 square foot at a depth of 1 inch.
Personally I love the super fine sand but I use the CaribSea Fiji Pink which is pretty popular which is slightly less fine than the gorgeous CaribSea Oolite. I have a slightly taller tank with a fairly dense amount of rock so I haven’t had any issues. Hopefully this info has been informative and helped steer you down the right path. Good luck and happy reefing!
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