Fluval M Series Aquarium Heaters

The Fluval M Series brings a designer touch to aquarium heating. Each heater is wrapped in heat and shock resistant borosilicate glass with a subtle mirror finish that reflects the colors of your aquarium, so it quietly blends into the background instead of standing out as a black tube. Set your exact temperature anywhere from 66 to 86 F (19 to 30 C) with the top dial, and enjoy the reliability of a heater crafted in Italy. Safe for both freshwater and saltwater.

Setting up a small tank? The preset Fluval P Series covers aquariums up to 15 gallons. Prefer fully electronic digital control? See the Fluval T Series. Pair any heater with a digital thermometer.

Features

• Mirror-glass that blends in. The reflective borosilicate exterior picks up the colors of your aquascape, so the heater visually disappears into the tank.
• Adjustable 66 to 86 F (19 to 30 C). Dial in the precise temperature your fish, shrimp, or corals prefer.
• Heat and shock resistant. Thick borosilicate glass stands up to temperature swings and everyday handling.
• Crafted in Italy. Built with premium components for consistent, long-lasting performance.
• Fully submersible. Mount it vertically or horizontally, completely underwater, near good flow.
• Fresh or salt water. Rated for freshwater and saltwater aquariums alike.

Choose Your Size

Match the wattage to your tank volume, and size up if your room runs cold. On larger aquariums, two heaters give more even coverage and a safety margin.

How to Use

Place the heater fully underwater near good flow, such as beside a filter outlet, so heated water circulates evenly. Let it sit for 15 to 30 minutes before powering on so the glass matches the water temperature. Set the top dial to your target, allow the tank to stabilize, and confirm with a thermometer. Because the M Series is glass, handle it gently and always unplug and let it cool before removing it from the water.

FAQ

What makes the M Series different?
Its mirror-finish borosilicate glass reflects the aquarium around it, so the heater blends in rather than standing out. It is adjustable and crafted in Italy.

What temperature range does it cover?
You can set it anywhere from 66 to 86 F (19 to 30 C) using the top dial.

Is it safe for saltwater?
Yes. Every M Series heater is rated for both freshwater and saltwater aquariums.

Which wattage should I choose?
Match the model to your tank size: M50 for up to 15 gallons through M300 for up to 80 gallons. Size up in a cold room, or run two smaller heaters on a large tank.