Thermometers
A thermometer belongs in an aquarium just as much as a filter – fish are sensitive to temperature fluctuations. Choose between classic glass thermometers with a suction cup in 11 and 15 cm lengths, or digital models such as UnionStar, Tetra TH35 or Sera. A digital thermometer is easier to read, while a glass one needs no batteries – just make sure to place it on the opposite side of the tank from the heater.
