UGH and what to do with the old CO2 generating fluid

Hey all,

I have a question regarding UGH (undergravel heating).  I am wondering if 
anyone has tried using a waterbed heated mounted onto the bottom of a tank 
to provide heating of the substrate.  The heaters are relatively expensive 
and at the lowest settings They should provide adquate heating, without the 
possiblity of breaking the tank.  The heaters consist of a large rubberized 
pad about 2' long and 1' wide with a temperature probe that goes back into 
the thermostatic control.

Anythoughts???  One the other thread I would like to add the concept of 
distillation.  You could simply seperate out the nasty yeast flavors and end 
up with a relatively pure alcohol product...but then again...the hard cider 
idea sound pretty appealling.  If I can get the champagne yeast propogating 
here...would be glad to send cultures to people :)

    John Davis (marooned in aggieland)
    Department of Biology
    jdavis at bio_tamu.edu
    jmd9261 at tam2000_tamu.edu