ok, the articles that involve diy
substrate heating have math in 'em... Not being a big fan of math, and with the limited resources available, here's what I've come up with;
I have a 50 watt 12 volt transformer that once powered a low-voltage halogen light.
I have approximately 12 feet of 30 gauge copper/tin insultated wire woven in a snake-like pattern on some craft canvas.
I have a 10 gallon aquarium, filled with 2 gal
of water for testing
The canvas is about 1/4" from the bottom glass suspended by some rocks
When I connect the wire to the transformer, the small amount of 30 ga wire that is out of the water gets warm, but the coils under the waters I cannot feel any temperature difference.
I assume that I must have too much resistance / too long of wire, and that is why it's not getting hot, or is my voltage too low? I first tried 5 and 9 volts, and the exposed wire didn't even get warm with them.
Should it get warm enough that you can feel it, or doesn't it work that way?
If I remember high school circuits class correctly, would running another 'snake' of wire near the first one, and wire them in parallel to the transformer, this should cut the resistance in half, which should generate more heat?