Hydor External heater

Hydor External heater

  • Instant water heater for installation outside tanks
  • The desired temperature can be adjusted precisely
  • Fits all standard external filters
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The Hydor external heaters are mounted in the filter hose of the external filter on the pressure side. The unique external heater for aquariums comes with the exclusive PTC (Positive Thermal Coefficient) technology. The self-limiting PTC heating element guarantees maximum safety against any risk of overheating. The exclusive technology and the high quality of the components guarantee a long lasting product. Suitable for canister filters and sump tanks.


  • External heating element 300 W with PTC system, suitable for all external filters
  • Absolutely safe - no risk of breakage or explosion in case of running dry
  • The patented heating element consists in the exclusive PTC system. Here, standard metal heating coils have been replaced by a plastic foil coated with resistant aluminium paste
  • Electronically controlled temperature regulation with function display


Hydor External Heater 200 W - 17 mm
Length 300 mm
Diameter approx. 80 mm
Fits hose 17 mm or 16/22 mm
Hydor External Heater 300 W - 17 mm
Length 300 mm
Diameter approx. 80 mm
Fits hose 17 mm or 16/22 mm


Power 8 °C heat up 10 °C heat up
200 Watt 100 - 200 Litres 100 - 180 Litres
300 Watt 200 - 300 Litres 180 - 250 Litres



Hydor has a vast product range containing high-quality filters, pumps and heaters that are technically up to date. Especially in aquascaping, the focus ought to be on the layout inside the tank and not on the technical equipment, e.g. the adjustable heater. External heaters by Hydor make it possible to place another part of the technical equipment you need for a planted tank outside your aquarium.

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Customer reviews

This item has been rated 4.6 out of 5 stars
18 Reviews
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5 Stars(14)
4 Stars(3)
3 Stars(0)
2 Stars(0)
1 Star(1)
Kasper N.
18th April 2019
Hydor - External heater
Hydor - External heater

Works perfectly fine, temperature is stable; easy to attach to the filter hose. A must have if you want to avoid seeing a heater inside the aquarium.

Aivis K.
Must have!
10th March 2017
Hydor - External heater - 300 W - 17 mm
Hydor - External heater - 300 W - 17 mm

Good quality for this price. I am exited from the item realy .Thank you aquasabyi for fast delivery to Latvia!

Gintare C.
Stable and easy to use
23rd December 2018
Hydor - External heater
Hydor - External heater

Keeps really stable temperature. Just finding difficult to clean as in and out flow opening smaller than inside. Nice not to see a heater in the tank

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