I bought 3 of these heaters, 2 for me and 1 for my granddaughter. They work great; I think my Bettas are nice and warm now. I'm told Bettas like warm water but I started out on 82 degrees and that was too warm - they got sluggish. I now have it set at 80 and they love it. Very fast shipping, packaged great. I am very happy with my purchase. Thank you Pet Mountain.
Barbara from Rio Rancho, NE