Cobalt Neo-Therm Pro 100W Review
A flat, shatterproof heater barely thicker than a phone, with an LED read-out and a tightly-controlled electronic thermostat. It hides against the glass and holds temperature to within half a degree.
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👍 Pros
- Ultra-slim flat body hides against the back glass — great for aquascapes
- LED display shows both the set and the current water temperature
- Tight electronic thermostat, accurate to about ±0.5 °C
- Fully submersible, shatterproof shell with auto shut-off
👎 Cons
- Costs more than a plain dial heater of the same wattage
- Flat shape can be awkward to position around some intakes
- Electronic heaters are harder to repair than a simple glass unit
The heater that disappears
Most heaters are a fat tube you try to hide behind a plant. The Cobalt Neo-Therm Pro is different: a flat, shatterproof body barely thicker than a phone that presses against the back glass and all but vanishes in a planted or aquascaped tank. An LED display reads back both your set temperature and the current water temperature, and the electronic thermostat holds it to around ±0.5 °C — so this is as much about looks as it is about precision.
Sizing the 100 W
Cobalt rates the 100 W version to roughly 30 US gallons, but size any heater by the water. Budget around 1 watt per litre (about 1.5 W/L in a cold room), which puts the 100 W Neo-Therm on a 60–100 L tank. As with every heater, oversize rather than undersize: a slightly larger unit cycles off sooner and stays steady, while an undersized one runs flat out and still loses ground overnight. The full watts-per-litre table lives on our aquarium heaters hub.
Slim, tough or classic?
If you want a display but do not need the slimline shape, the Fluval E100 gives you a screen and drift alert in a round guarded body. If you would rather spend less and just want a shatterproof workhorse, the Aqueon Pro 100W is the value pick, while the bare-glass Eheim Jager 150W remains the accuracy benchmark for those who trust glass. Match the heater to the tank on our aquariums page and pair it with the right filter.
The heater for a tank you want to look tidy. It vanishes against the glass, reads its own temperature back on an LED, and holds it to half a degree — the pick when appearance matters as much as accuracy.
Cobalt Neo-Therm Pro 100W — frequently asked questions
How many watts do I need?
Budget roughly 1 watt per litre in a normally heated room, and about 1.5 W/L if the room is cold. So the 100 W Neo-Therm suits a 60–100 L tank. If you are between sizes, oversize rather than undersize — a larger heater cycles off sooner, while an undersized one runs constantly and still struggles on a cold night.
Why choose the flat Neo-Therm over a round heater?
Two reasons: looks and safety. The slim flat body presses close to the glass and all but disappears in a planted or aquascaped tank, and the shell is shatterproof rather than bare glass. You also get an LED that reads back the actual water temperature, so you are not trusting a dial alone.
Is an electronic heater reliable long-term?
The Neo-Therm's thermostat is accurate and holds temperature well, and the shatterproof body protects it from knocks. The trade-off versus a simple glass heater is repairability — if the electronics ever fail you replace the unit rather than a part, so a cheap independent thermometer as a cross-check is still worth having.
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