I have to agree that the on and off will wear out the heater quicker. I've also had heaters fail in both the on position (and I've cooked the fish) and in the off position (which I discovered before they died). With two smaller heaters, if one sticks on it can only heat up the tank so far and the other probably won't come on at all. Eventually you'll notice, but probably little harm will be done in the interim. If one fails in the off position, even if the remaining can't heat the tank by itself, the fish tend to hover around the working heater. You'll notice that and correct the situation. My problem has been finding very low wattage heaters for small tanks at my local fish dealers who seem to feel bigger is better. So, I get them through the mail or when I'm visiting out of town and of course, checking out the shops. __________________________________ Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want. http://antispam.yahoo.com/tools ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/