Reefs.org Forums

[MattM]

O.K. Gang,

Here are photomicrographs of various substrates. All pics are at 40X.

Southdown Tropical Play Sand


Carib-Sea Aragamax


Quickrete Play Sand

[reefworm]

Matt,
Thanks for posting those! I'd wondered about the variation of particle size in the SD sand - looks like a good spread of sizes. Any way to post them with some sort of scale superimposed to get a measure of grain sizes?

regards,
rw

[MattM]

Be careful what you ask for, you might get it! [img]images/smiles/icon_smile.gif[/img]

Southdown at 40X with measurements

[pghflame]

Very interesting...really shows the SD looking a lot like the carib sea....and the quikrete like something you'd never want to use (nor should you anyway).

[liquid]

There's nothing wrong w/ using silica sand. [img]images/smiles/icon_smile.gif[/img]

Shane

[liquid]

BTW...Matt: do you want seived fractions done on any of the sand products? I have seiving equipment available if you'd like a particle size distribution done on any substrates. Here's the piece of equipment I'm talking about and how it's done:

http://www.geog.plym.ac.uk/labskills/psapg2.htm

Fire me off an email if you're interested. My email is in my profile. [img]images/smiles/icon_smile.gif[/img] Might be interesting to compare MM as well...

Shane

[liquid]

Matt: Also forgot to mention: if you'd like to know the organic content of MM, let me know. I can ash the sample per the following proceedure to give you an indication of how much of MM is organic:

http://www.geog.plym.ac.uk/labskills/ompg.htm

I remember you mentioned that you have seen sticks and whatnot in the product. Might be an interesting test...

Shane

[reefworm]

Terrific! Looks like it's pretty close to the sizes Dr. Ron recommends. Liquid's test of size distribution would be the other factor. But if it is the actual sand that's collected, I would think it would be close to the ratios that Dr. Ron suggests for constructing a sandbed. That sure makes it simple! [img]images/smiles/icon_biggrin.gif[/img]

thanks again, guys!
-rw

[MickAv8r]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by LiquidShaneo:
<strong>There's nothing wrong w/ using silica sand. [img]images/smiles/icon_smile.gif[/img] </strong><hr></blockquote>

While the sand itself is relatively inert (what possible contaminants may be in quickrete are unknown) it's definitely not as desireable as oolitic aragonite. Look at the pics and you see all sorts of sharp edges that are not going to be as kind to softbodied infauna as the ooliths in the SD/CS sand.

[moe_k]

Matt & gang,
Those are excellent pics, and thanks for posting them!

[SPC]

Thanks for the pictures Matt and Tom!
Posted by Tom:
Look at the pics and you see all sorts of sharp edges that are not going to be as kind to softbodied infauna as the ooliths in the SD/CS sand.

-I agree with this statement, Dr Ron and Rob Toonen have both stated that these sharp edges can be very detrimental to many of the sandbed infauna.
Steve

[liquid]

Tom: I was referring to the myth that silica based sands cause problems with diatoms and not the sharper edges on the particles causing problems w/ infauna. [img]images/smiles/icon_smile.gif[/img]

Shane

[MickAv8r]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by LiquidShaneo:
<strong>Tom: I was referring to the myth that silica based sands cause problems with diatoms.</strong><hr></blockquote>

Yeah Leng Sy's Miracle Mud proved that! [img]images/smiles/icon_biggrin.gif[/img]

[Biogeek]

Cool pictures, Matt - it's great to see this sort of stuff being posted!

I haven't had a chance to do the sieving on anything other than the Southdown sand, but I have posted the particle size breakdown of it here.

This image looks pretty close to what I found with the bags I tested as well:
+ 500 um (= 0.5 - 2.69 mm) 14% (largest particle 2.69 mm)
+ 300 um (= 0.3 - 0.5 mm) 32%
+ 250 um (= 0.25 - 0.3 mm) 16%
+ 180 um (= 0.18 - 0.25 mm) 20%
+ 125 um (= 0.125 - 0.18 mm) 13%
+ 100 um (= 0.1 - 0.125 mm) 3%
+ 50 um (= 0.05 - 0.1 mm) <1%
+ 50 um (= 0.001 - 0.05mm) <1%

This is pretty close to the particle size distributions that Ron and I have recommended for deep sand beds.

Rob

[ April 22, 2002: Message edited by: Biogeek ]</p>

[jamesw]

Thanks Matt, Rob, Shane!

This looks like the beautiful beginning to an Advanced Aquarist's "Short Take" article to me. You might want to grab some of that "arragalive" as well...

What about a particle size breakdown of the LS that Walt Smith ships from Fiji? That is some pretty coarse stuff.

Cheers
James

[liquid]

If Tom or Rob have any samples they'd like sieved, fire off an email to me and I'll run the tests. I've got the equipment and the test is pretty straight forward but I just don't have access to all of the different substrates out there. I think I'd need about 600 grams of substrate to do the tests in triplicate for each substrate. I think it would be very interesting to see what the particle size distribution of some of the commercial products are. [img]images/smiles/icon_smile.gif[/img]

Also, in regards to ashing a sample of Miracle Mud: performing this test in my mind would clinch the argument if it's a formulated product or if they're just mining the stuff from someplace. If it's formulated, odds are it will have very little or no organic component to it (thus very little to no ash) whereas if it's mined it should have a certain amount of ash to it.

Shane

[cwa46]

If you want to "assume" the sharp edges of silica sand cause harm, you are doing it without any type of proof. Where are the dead and injured critters that it hurts.
I would like to see some pictures of sand particles after they are covered with the biological coating all sand gets in a tank. It not only holds sand together and helps keep it from being blown about, it reduces the ability of aragonite to dissolve and so reduces the buffering capacity, and I believe it will cover most of the rough edges of silica sand.
In any case, the pictures of the sand in no way gives any evidence that the shape of the sand will hurt or kill sand dwellers.

[SPC]

Posted by cwa46:
If you want to "assume" the sharp edges of silica sand cause harm, you are doing it without any type of proof.

-No assumptions here. Dr Ron has said in the past that substrate with sharp edges will injure soft bodied animals such as we find in our DSB.
Steve

[ May 05, 2002: Message edited by: SPC ]</p>

[MattM]

And, as an anecdotal example...

We put a Miracle Mud system on our quarantine tanks some time ago to experiment with. It has the same sort of sharp edged silica particles as the quickrete sand. A new tank with aragonite sand added to this system develops a good level of sand fauna in a week, but it took over six months to develop similar levels in the MM.

[2poor2reef]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote

it reduces the ability of aragonite to dissolve and so reduces the buffering capacity

I wish someone would explain this to me as I hear it all the time. Does aragonite really dissolve at a ph of 8.3? I've used aragonite sand for years and never noticed any reduction in the volume of the bed. I understand how it dissolves in a calcium reactor at lowered ph but in our tanks?