>>>The heaters (waterbed heaters) are relatively expensive and at the lowest settings They should provide adquate heating, without the possiblity of breaking the tank. I should have said that the heaters are INEXPENSIVE!!! John Davis (marooned in aggieland) Department of Biology http://http.tamu.edu:8000/~jmd9261 jdavis at bio_tamu.edu jmd9261 at tam2000_tamu.edu ----------oOOo----oOOo-------------------------------------------------