Ultra Heater D&N 25W – aquarium heater

This 25 W heater suits hobbyists keeping small freshwater, marine, paludarium or aquaterrarium setups in tanks of 10–25 L. Its electronic thermostat holds a stable water temperature, and the day-and-night function lowers and raises the temperature automatically to mimic a natural daily cycle.

Why it matters

• Precise control: the electronic thermostat maintains temperature within ±0.25°C across a 20–33°C adjustment range.
• Day-and-night function: the heater automatically varies water temperature between cooler nights and warmer days, which the manufacturer links to more natural conditions for fish and aquatic plants.
• Simple operation: a single ONE-TOUCH button and an LED ring show both the current and the programmed temperature.
• Safety features: a built-in thermal cut-out protects against overheating, and an additional overheating prevention system works during hot periods. The housing is unbreakable.

Specifications

• Power: 25 W
• Tank volume: 10–25 L
• Temperature range: 20–33°C
• Temperature precision: ±0.25°C
• Dimensions: 5 x 2.5 x 16.3 cm
• Weight: 1 kg

What it works with

The heater fits tanks of 10–25 L, which covers small freshwater and marine aquariums as well as paludariums and aquaterrariums. The manufacturer states that it can also be used in terrarium pools and in tanks with larger, strong fish or water turtles. Its very flat profile allows discreet placement, and the double-sided hanger makes installation straightforward.