I’ve been scuba diving enough to know how much the temperature can fluctuate between shallow water, and deeper waters, and I would expect even a mountain stream picks up degrees the longer the sun beats down on it… and there must be several degrees difference in the Amazon, between clear areas where the sun beats down on it, ( weather, forested by man, burned out, or natural ), and flowing in heavy jungle areas that never see the sun… I would suspect the smaller the body of water, the bigger the fluctuation would be, and at this point, that is “natural” my 3 season porch tank ( a 55 gallon aquarium ) is fully in the shade, yet at this time of year, where I live, the low temps and high temps for the day, can be 20 degrees different ( not just occasionally, often ) it’s a day like that today, and my aquarium is going to varry from the low this morning, near the set point for the heater ( 65 degrees ) to 75 degrees by the time it starts cooling off again ( 10 degrees ) the fish are doing quite natural… I’m not sure why so many people freak out over 1-2 degrees in their tanks???
