The Fluval T Series is the the fourth model of water warmers by the venerable Hagen brand from Canada. Most companies have one, maybe two lines of aquarium heaters but with the Fluval T Series Hagen completes their heater catalog cleverly made up of the T, E, M, and P series.
The Fluval P Series are entry-level preset heaters for smaller tanks, the M series are more contemporary classic glass design while the E series are a more advanced electronic aquarium heater with electronic thermostat and a built-in LCD temperature readout. The Fluval T Series heaters seem to slot in between the M and E series with electronic temperature control via a top mounted adjustment ring.
Although Hagen disclaims that the T Series is only for use in freshwater aquariums, we can still appreciate that the heater has an automatic shutoff when removed from the aquarium water, and it incorporates a clever 360° indicator light ring that is red when it’s heating, and blue when it’s reached the desired temperature. The shutoff and high visibility indicator are welcome features that you’ll only enjoy in a freshwater aquarium but we can long for these useful features in a future saltwater-safe aquarium heater.