I have a Eheim Jaeger Trutemp heater for my small tank. I noticed that there are temperature fluctuations. The temperature goes between 25.4 to 26.3. I don't think I've ever encountered this before. Is it possible that I set it too low? Meaning it doesn't kick in until the temperatures reaches 25.4? If I were to raise it, would that not mean that it would get warmer than 26.3? I'm really confused.