ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************

One reason for using deionised water is that 'hard' water can apparently
form deposits on the vibrating surface of the transducer.

The other reason is to help avoid giving your visitors legionaire's disease
by flinging bacteria-laden water droplets out into the air. Deionised water
is less likely to nourish bugs. Also, a strict cleaning and water-changing
regime are essential for these things.  

Some years ago, a neighbour of ours had one in her home as a decorative
feature and topped up the water without ever changing it. I spent an evening
sitting close beside it and she scoffed at me when I suggested it could be a
health hazard. Within a week I was hospitalised with pneumonia. I've since
been told that any connection is most unlikely but I personally remain
cautious about these things. I noticed that the 'fogger' ornament quietly
disappeared from my neighbour's home.

Promoting public engagement with science
through a contagious delight in phenomena
*
[log in to unmask] * http://www.interactives.co.uk
*
Give people facts and you feed their minds for an hour.
Awaken curiosity and they feed their own minds for a lifetime.
*
Ian Russell   (Twitter: ianrusselluk)


-----Original Message-----
From: Informal Science Education Network
[mailto:[log in to unmask]] On Behalf Of Erich Rose

I've used those as well for a tornado vortex machine. It was medium sized
version maybe 36" diameter x 48" tall tornado.  We made sure to use
deionized water which worked better (but don't ask me why).  

***********************************************************************
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.

The ISEN-ASTC-L email list is powered by LISTSERVR software from L-Soft. To learn more, visit
http://www.lsoft.com/LISTSERV-powered.html.

To remove your e-mail address from the ISEN-ASTC-L list, send the
message  SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]