AquaLighter aHEATER MINI, 10 W is a compact aquarium heater for tanks up to 15 L from the Ukrainian company COLLAR. A built-in thermostat holds 25 ±1 °C: once the water reaches 25 °C, the heater switches off automatically. A two-colour LED shows the mode: violet means heating, blue means powered on but not heating. The housing is made of an ultra-strong polymer that resists knocks and sudden temperature changes, rated IPX7, with overheat protection. It runs on 230 V at 10 W. The manufacturer's warranty is 2 years.
Why a small tank needs a heater
The smaller the tank, the faster the water cools at night and warms by day. For most tropical fish and shrimp, such swings are harmful: immunity drops and fish fall ill. A thermostatic heater keeps the temperature stable. For bettas, guppies, neons and shrimp, 25 °C works well for many. On setting up a tank, see aquarium for beginners: what to buy.
Key specs
| Parameter | Value |
|---|---|
| Type | submersible thermostatic heater |
| Power | 10 W |
| Tank size | up to 15 L |
| Temperature | 25 ±1 °C, fixed |
| Indicator | violet — heating, blue — on, not heating |
| Protection | IPX7, overheat protection |
| Warranty | 2 years |
| Brand | AquaLighter (COLLAR), Ukraine |
Pros
- Compact. Barely visible in the tank.
- Automatic thermostat. Holds 25 °C.
- Clear indicator. You can see if it's heating.
- Impact-resistant housing. Copes with sudden changes.
- Overheat protection.
- A 2-year warranty.
Cons
- The temperature isn't adjustable. 25 °C only.
- Only up to 15 L. Not powerful enough for bigger tanks.
- You need a thermometer. For monitoring.
- Not for coldwater fish. Goldfish usually don't need heating.
How to install it
Place the heater fully under water, ideally near the filter outlet so warm water spreads quickly through the tank. Plug it in only once it's submerged. Unplug it before water changes and plug it back in once the level is restored. Monitor the temperature with a separate thermometer.
A fixed 25 °C — plus or minus
A fixed temperature is handy for beginners: nothing to set, and 25 °C suits many popular tropical fish and shrimp. But if your fish need a different temperature — warmer water for discus, for example — you'll need an adjustable heater. Check your fish's requirements before buying.
Which tanks it suits
The manufacturer specifies up to 15 L: nano tanks, betta bowls, breeding boxes and shrimp tanks. It suits small sets such as the Priroda Mini Cube 9.5 L. Bigger tanks need a more powerful heater.
How to tell it's working
Right after you switch it on in cool water, the indicator glows violet — it's heating. Once the water reaches 25 °C, it turns blue: the heater is on but not heating. If the indicator stays violet for a long time while the thermometer reads well below 25 °C, check whether the tank is too big or standing in a draught or by a cold window.
Safety
The housing is IPX7-rated with overheat protection. Even so, never run the heater out of water, and don't lift it out while it's on — let it cool first. Make sure fish don't rest right against it, and check the housing and cable for damage regularly.
Care
When cleaning the tank, unplug the heater, let it cool and gently wipe deposits off the housing with a soft sponge. Avoid abrasives and chemicals.
What else you'll need
A stable ecosystem also needs a filter, lighting and water conditioners — such as Rikka Aqua Start with beneficial bacteria. All equipment is in the aquarium equipment section.
Who it suits
Owners of nano tanks, betta bowls, shrimp tanks and breeding boxes up to 15 L with tropical fish that are happy at 25 °C — especially beginners who'd rather not set anything up.
Verdict
The AquaLighter aHEATER MINI is a compact 10 W heater for tanks up to 15 L with an automatic 25 ±1 °C thermostat, a two-colour indicator, an IPX7 impact-resistant housing and overheat protection, backed by a 2-year warranty. The downsides are a non-adjustable temperature, power only for small tanks, and the need for a separate thermometer.
FAQ
What tank size is it for?
Up to 15 L.
What temperature does it maintain?
25 ±1 °C.
Can the temperature be adjusted?
No, the thermostat is fixed.
What do the indicator colours mean?
Violet means heating, blue means on but not heating.
What's the power?
10 W.
Does it have overheat protection?
Yes.
What's the warranty?
2 years from the manufacturer.
