Crushed Coral vs. Live Sand

TommysGirl · 10-05-2006, 07:51 PM

Ok I thought of another question

Is it necessary to have live sand? I am using crushed coral right now. Can I replace it with live sand, at a later time? Are there certain reasons that people chose one or the other? Thanks so much!

ahill3780 · 10-06-2006, 05:30 PM

It isn't necessary to start with live sand, or live CC in your case. The sand/gravel will eventually become live on its own, just not fast. Using live sand has definate benefits but its use is not a must.

When you look at the technical side of it you'll find that sand offers a larger 'surface area' for the colonization of bacteria which makes it appealing for many, if not most, hobbiests. There are benefits that CC offers that sand does not, but the main focus with any substrate tends to be on biological filtration.

Biological filtration, which relies on nitrifying bacterial colonies to consume and convert wastes in the tank environment, work more effeciently with larger colonies. Large populations will need lots of realestate to colonize, which is where the substrate comes in. These bacteria do not swim freely through the water, they settle on porous surfaces like the substrate, decor, filter media, piping and powerheads, etc.

You can safely fit more sand/gravel in a tank without disturbing the environment than you can decor, powerheads, filters, etc. so the main focus on substrate becomes focused on its ability to support better biological colonization. Crushed Coral gravel will work just fine, and theres nothing wrong with using it, but the sand will work better because of its ability to support larger bacterial colonies.

The way I would describe it, which is not at all scientifically backed (more like my guesstimation.

), is a 1" bed of sand will give about the same filtration capability of a 3-4" bed of CC gravel.

Although many people like to rely on their filtration equipment for all of their filtration needs, including biological, it is my opinion that having a colonized substrate is essential to ensuring the continued stability of your aquarium. Filters with biological media included are all well and good, and will certainly contribute their part to the extraction of waste, but these should not be relied upon to shoulder the whole burdon on its own.

HTH,
Aaron

TommysGirl · 10-06-2006, 07:08 PM

Thanks so much for the clarification Aaron. You really know your stuff!! I'm finding that the more I learn and the deeper I get into saltwater, the more I realize I don't know!!

Thanks again for the clarification!

TommysGirl · 10-17-2006, 02:24 PM

Ok, I understand why live sand is more beneficial than crushed coral now, but I'm still a little confused about how to add it. Does live sand need to be cured or quarantined? I would really like to add live sand to my system because down the road their are some fish and inverts I'd like to add that do best with sand. So my questions are 1) Do I need to quarantine/cure or do anything to prep "live sand"? 2) Do I need to remove my crushed coral to add live sand, or could the two be mixed? Would it be best to remove the fish and rock already in the tank as well? 3) Any suggestions on where I could order live sand?

Thanks so much in advance!

ggmichael · 10-17-2006, 05:14 PM

For us, we alreadh had CC then later added the LS. We just put the LS over the top of the existing CC (which we had vaccumed a bit so some had been removed anyway). We also left the LR in place and used a turkey baster to direct the LS to where it was needed; everything seems to be working fine.

Loman · 10-17-2006, 06:13 PM

The live sand is shiped with water in the bag and the critters are mostly alive. It may cause a mini cycle but I do not think you will need to cure it. If I did anything I would add it a bit over time

TommysGirl · 10-18-2006, 03:02 PM

I guess my concern is that if I'm switching from crushed coral and I place the sand on top of it, then I'll have to mix them up if I ever upgrade or do something different with the tank. Can you further clarify the difference between "live sand" that you see advertised along side live rock and the "live sand" that is in bags (the cheaper stuff I mean-usually reads something about live argonate sand). I read that it contains a biofilm of bacteria? Either way, it will be a few months before I do anything-I just want to have all my i's dotted and my t's crossed before I dive in

!! Thanks so much to all of you for your help!!

Tommy Gun · 10-18-2006, 04:07 PM

I honestly do not understand completely what you mean by the two types of live sand. I bought live sand in the bags for about a dollar a pound and just dumped it in. When I needed a little bit more, I was actually able to buy the sand that my LFS used in its own established tanks. I don't really think that is a common situation to be able to buy that sand, but I really kissed a lot of butt to get it!

I think the main difference between the crushed coral and live sand is simply the surface area that is available for bacteria to grow on. Since crushed coral is larger in size (granule vs. granule) than actual sand, it has more spaces between it when in the bag. The live sand is smaller and more granules can fit into the bottom of your tank, so there is more surface area.

Someone can correct me if I am wrong, but eventually anything you put into your tank as a substrate is going to end up becoming "live" in the end. It is just a matter of being able to support more or less life.

Argonite sand is just another alternative for a substrate. I found this really good resource for learning more about the types of substrates:

Choosing a substrate

I think this will help you out alot when trying to decide what to buy. Then I would assume that price is going to be the only factor that you will really have to study up on.

Shawn D · 10-18-2006, 04:45 PM

I dont mean to thread jack, but I used a mix of crushed coral and sand. Is this a good idea?

Tommy Gun · 10-18-2006, 05:36 PM

I do not think mixing can hurt. I have seen 'mixed' substrates for sale at one LFS around here. I cannot remember the brand, but it was a black sand, with crushed coral and live sand, which if I had seen before, I would have put in my own tank. It was expensive though, 30 bucks for like 15 or 20 pounds.

I also recall reading a thread on this site (I think, sorry if I am wrong) about doing the same thing and it was no problem.