Akari_32
The Tetra Brand pre-set heaters are great (unless you want to fight ich without meds, then they suck LOL). They are cheap too. I got the 2-15 for about $12 and the 10-30 for about $19. Tetra has a great warentee, so if it doesnt work, you can send it back to them and they'll send you a new one. This last for two years, I think.
=OOOOOO I didn't know you could send them back if they don't work, do you need your receipt and the packaging? I have some heaters that definitely are not keeping my water warm enough.