I would suggest contacting someone at a water garden place like Lilypons
(www.lilypons.com).  They have complete information about creating water
gardens out of just about anything, like old tubs and stuff  They have
information about how to seal these things to prevent leakage, and since
many people put fish in the water gardens, they should know how to do it
without toxicity.

 

 

Betsy True 

Alexandria, VA 

 

Check out my website: 

http://www.betsytruedesigns.com 

 

See Lynda Prioleau's website: 

http://www.matlyndesigns.com