Originally Posted by deso
(...) For the heater, I'd bump that up to a Hydor Theo 25 or 50 watt adjustable. I think you can find one of those for 20$ or so on Amazon, much less if you buy from one of the third-party sellers linked on the website. Those 15$ mini-heaters aren't adjustable and could freeze or fry your fish. Plus, I'm not sure that such a low wattage will heat a 5 gallon at all.
You were not the only one recommending something more "serious". I ended up getting the Aqueon Pro 50 with the power monitor light.
Thank you for the recommendation.