do I have enough live rock?

[Ninong]

If you order sand online, the shipping will probably cost as much as the sand.

Looks like most of the online vendors are just offering that so-called "live" sand, such as $17.95 for 20 lbs of this stuff. No idea how much shipping would be from Indiana to Minnesota.

[craqerjaq]

this stuff is about all I can find and it seems that for 7-8 bucks per 10lb bag at Petco is the way to go...just need them to order more since I saw 3 on the shelf. You're right on shipping though...just not worth it.

[Ninong]

That stuff is really quite large: Premium Aragonite Substrate has a 1.2-1.7mm diameter size. That's about the same size as Florida Keys sand.

See if they can order anything smaller.

P.S. -- If that's all you can get, it will work but it's a different approach. My preference would be for a particle size mix of 0.1-1.0mm.

To understand what I'm talking about, take a look at the particle sizes of the various Carib-Sea dry aragonite sand products.

[Ninong]

What's in your tank already? I'm talking about the 40 lbs of "live" aragonite sand. What brand is it? Product name?

[craqerjaq]

Nature's Ocean stuff Bio-Activ Live® Aragonite Natural White #1

package says .5mm-1.7mm but in all honesty most of the sand is on the smaller particle end...there are a few small shell bits and nothing big or sharp. I know the stuff at Petco is pretty small particle size...yup look here exactly what you recommended. Would there be any need to mix up the sand in the tank once I add the new...I guess to get it spread around and into the existing sand...or just put the smaller stuff on top and let it be?

for the hell of it I went to Petco's site to see what shipping would be on 8 bags:
Subtotal:

Subtotal: $55.92
Estimated Shipping and Handling: $47.92
Sales Tax: TBD
Total: $103.84

Driving 5 miles across town is far less painful.

[Ninong]

Nature's Ocean stuff Bio-Activ Live® Aragonite Natural White #1

package says .5mm-1.7mm but in all honesty most of the sand is on the smaller particle end...

That's what I expected. It's better if the small stuff represents the largest portion of the mix.

I know the stuff at Petco is pretty small particle size...yup look here exactly what you recommended.

Actually that's even better than what I was talking about. I said you should look for something in the 0.1-1.0mm range and the stuff you linked is 0.1-0.5mm.

Would there be any need to mix up the sand in the tank once I add the new...

No.

...or just put the smaller stuff on top and let it be?

Just put about 1/2" of the new stuff on top of your existing sand bed without mixing anything up. Then wait a week before adding some more new stuff.

Driving 5 miles across town is far less painful.

Shipping is usually as much as the sand itself. It's much better if you can find some within driving distance.

[craqerjaq]

ok I was able to get 30lbs of this stuff and wow it's fine sand. the only problem I really have is the distinct line the two layers are presenting when I add the new stuff. I know there's no need to mix it up a little but it can't hurt right? I'll probably just do the perimiter so I don't see the 2 sand layers...slight ocd problem with things being consistent and ordered (yet my apt is still a mess lol ).

I like this fine sand though...makes me want to go to the beach, especially since there's a blizzard outside.

[Ninong]

...when I add the new stuff. I know there's no need to mix it up a little but it can't hurt right?

Yes, it can. That's why my answer was No in bold. Do NOT disturb your existing sand bed. Just add some of the new stuff on top of it.

Eventually, if your sand bed is deep enough, you will see distinct layers, and that's a good thing. It means your sand bed is working the way it's supposed to work.

[Ninong]

I like this fine sand though...makes me want to go to the beach, especially since there's a blizzard outside.

It's 76°F down here right now.

[Ninong]

Dr. Rob Toonen's article on how sand beds work: Part One and Part Two.

Dr. Ron Shimek's article on how sand beds work: here.

Reef Aquaria As Ecosystems -- Excellent article by Dr. Ron Shimek on the importance of sand beds, including a discussion of energy and material pathways.

Both of those guys have pretty much the same approach to sand beds. Rob give a minimum of about 3.5" depth and Ron gives a minimum of 4" depth.

There are other approaches to the depth of a sand bed and its composition. Certainly a sand bed of only 2.5" depth is capable of some denitrification but one slightly deeper is better.

And, as Rob says in his article, a fine particle sand bed may not be the best choice for an SPS-dominated tank with very strong water current. However, many hobbyists do run SPS-dominated tanks (e.g. kevinpo) with fine particle DSBs and fairly strong water current.