It's an absolutely fine way to heat an aquarium. Can be slightly more energy efficient than a tube heater sitting in a corner of the aquarium due to the convection of the heat rising up realtively evenly into the watercolumn. Otoh, that diff is probably negligible if you're using an inline heater or sump heater or have good water circulation in the aquarium. A 12 volt system, run off of a step-down transformer, won't trip a GFCI if the heater shorts to the water unless the heater has a ground wire. A 110-120 volt system will trip a GFCI if the heater shorts, but for that 1/250th of second, the jolt will have more impact than a 12 volt system ;-) I'd say the risks about even out between the two types. With a 12 volt system the cost of the transformer alone can be brutal. Buying cables won't directly hurt your aquarium, whether in use or not, except that they will probably cost more to purchase and, if you later replace them with another heater, there's that additional expense. If you are limited in how much you can spend on aquaria, buying the more expensive item that provides negligible benefits can hurt a tank by consuming financial resources that might be applied benefically. Scott H. > The apparent consensus that, while undergravel heaters > may have some value, there are better things to spend > your money on seems right on. > > If you want to try them though, there is no reason not > to. AZOO makes a very serviceable 110 vac cable kit that > is fairly inexpensive. If you later decide not to use > them there is no harm done as you can simply turn them > off and leave them in the tank. Don't get too caught up > in the 110 vac versus 12 vdc debate. You should be using > a GFI breaker on any tank and the cables that I've used > are very well made. I've used three sets of the AZOO > cables for a combined 6 years with no issues. > > I think Aquatic Eco Systems carries them. > _Aquarium Plants_, Christel Kasselmann, will be speaking about plants and tanks at the NEC 30th Annual Convention It's not too late to register. Get info at: http://www.northeastcouncil.org/html/modules.php?op=modload&name=News&file=index _______________________________________________ AGA-Member mailing list AGA-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/aga-member