Aquael Ultra Heater Day & Night 25W – Unbreakable Aquarium Heater for 15–50L

The Aquael Ultra Heater Day & Night 25W is a premium fully submersible aquarium heater designed for aquariums between 15 and 50 litres. Equipped with Aquael’s innovative DAY & NIGHT technology, it accurately maintains water temperature throughout the day or recreates the natural day and night temperature cycle found in rivers and lakes, providing ideal conditions for even the most sensitive aquarium inhabitants.

At the heart of the heater is a highly precise electronic thermostat with an accuracy of ±0.25°C, ensuring exceptional temperature stability. Thanks to the integrated Smart Heating System, the heater adjusts its power intelligently, warming the water gradually without sudden temperature fluctuations that could stress fish or other aquatic animals.

The unique DAY & NIGHT mode allows users to programme separate daytime and nighttime temperatures. A built-in light sensor automatically detects changing light conditions and smoothly switches between day and night settings, creating a more natural environment that supports healthy biological rhythms.

Unlike traditional glass heaters, the Ultra Heater features a shatterproof plastic housing, making it exceptionally safe for aquariums containing large fish, aquatic turtles, stingrays, or other sensitive species. The intuitive ONE TOUCH control system allows easy temperature adjustment, while the integrated display clearly shows both the programmed and current water temperature.

The heater also includes an integrated thermal safety cut-out to protect against overheating, ensuring reliable and safe operation every day.

Key Features

• Fully submersible electronic aquarium heater
• Power: 25W
• Recommended for aquariums 15–50 litres
• Innovative DAY & NIGHT operating modes
• Automatic day/night temperature switching via built-in light sensor
• Smart Heating System for smooth, intelligent heating
• Ultra-precise electronic thermostat (±0.25°C)
• Adjustable temperature settings
• Displays both current and programmed temperature
• Shatterproof plastic housing
• Integrated overheating protection
• Even heat distribution
• Functional double-sided mounting bracket

Technical Specifications

• Brand: Aquael
• Model: Ultra Heater Day & Night
• Power: 25W
• Recommended aquarium size: 15–50L
• Temperature accuracy: ±0.25°C
• Heater length: 16.3 cm
• Heating system: Smart Heating System
• Operating modes: Constant temperature / DAY & NIGHT
• Housing: Shatterproof plastic
• Safety: Integrated thermal cut-out
• Type: Fully submersible electronic aquarium heater