Thanks Inga. I bought them at my LFS. They would give me a full refund if I had the receipts. Which of course I don't, because I bought them several months ago. I'm going to go there tonight and see if we can work out a store credit or something.
I think he is carrying Eheim heaters now, but he only had larger watt ones last time I was there. I think another place in town carries the Aqueons. I'll shop around some.
Thanks for the Dr. Foster's and Smith suggestion. If I don't find heaters locally, then I'll give them a try.
I did get a bristlenose pleco and 5 Cherry Barbs this week for my 20 gallon long, so I will focus on enjoying them and worrying less about heaters!