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What don't you like about the plastic material? In our experience it  
has the following advantages (and disadvantages):

1) It is less dense than gravel or sand, so features form in less  
space with lower flow rates (this is good).
2) It discourages the growth of microorganisms because it is inorganic
3) the mix of different colors often follows a mix of different  
densities. Interesting features occur as slightly different densities  
settle out at different places in flood plains and along bends in rivers
4) less abrasive than sand or gravel - an important consideration  
because small amounts of it work their way into nearby exhibits

The only disadvantage that I know of are:

1) more expensive than sand, gravel, walnut shells, etc.
2) colors are not naturalistic.


On Jun 15, 2009, at 5:08 AM, Robert Schmitt wrote:

> ISEN-ASTC-L is a service of the Association of Science-Technology  
> Centers
> Incorporated, a worldwide network of science museums and related  
> institutions.
> *****************************************************************************
>
> Hello all,
>
> Our stream table came with a plastic sand-like media that we aren't  
> satisfied with. What sands have you used in your stream tables to  
> greater success?
> Has anyone used Ward's sand-gravel mix, with various sediments, and  
> has it been successful?
>
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Joe O'Connell
Creative Machines Inc.
3113 East Columbia Street
Tucson, AZ 85714
(520) 294-0939
(800) 861-7937 toll-free in North America
(520) 294-0848 fax

We create objects and environments that encourage
creativity, support social interaction, and inspire self-confidence.

http://www.creativemachines.com
http://www.ballmachinesculptures.com








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For information about the Association of Science-Technology Centers and the Informal Science Education Network please visit www.astc.org.

Check out the latest case studies and reviews on ExhibitFiles at www.exhibitfiles.org.

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