Small aquarium heater and fish tank heaters
From thumb-size heaters for desk bowls to 500 W tubes for big tanks — every DaToo aquarium heater lists the tank size it's made for.
Aquarium Heaters (10 results)
Heater sizes at a glance
| Model | Power | Tank / range | Price |
|---|---|---|---|
| Mini Heater 25W | 25 W (100–300 W versions) | 1–6 gal (25 W) | from $7.99 |
| Flat Heater 6W | 6 W | Up to 2 gal | $8.79 |
| Betta Flat Heater | 10 W or 30 W | 1–1.5 gal (10 W), 3–5 gal (30 W) | from $14.79 |
| LED Display Heater | 50 W / 100 W | 2–10 gal (50 W) | from $12.79 |
| D1 Adjustable Heater | 25 / 50 / 100 / 200 / 300 W | 63–89°F | from $7.99 |
| Dial Heater | 100 / 200 / 300 W | 20–30 gal (100 W) | from $9.98 |
| 300W Knob Heater | 300 W | 50–70 gal | $12.79 |
| 500W Heater | 500 W | 40–105 gal | $16.99 |
| Titanium 500W Heater | 500 W | $28.99 | |
| Inline Heater 300W | 300 W | $49.99 |
Choosing a small aquarium heater
From a 6 W flat pad for a desk bowl to a 500 W titanium tube for a 105-gallon tank.
Read more
Why a fish tank needs a heater
Tropical fish come from warm, stable water. In a home aquarium the habitat cools every night, and small tanks and bowls cool fastest. Fish tank heaters keep the water inside the comfortable range automatically, which is basic care for betta, guppies, tetras, shrimp and most planted aquarium setups — freshwater and saltwater alike.
How many watts do I need?
About 3 to 5 watts per gallon in a heated room, more if the room is cold. A 5-gallon betta tank is fine with 25 W; a 20-gallon tank with 100 W.
Submersible or flat?
Submersible tank heaters are glass or titanium tubes that sit fully under water and suit most aquariums. Flat pads stick to the inside of small bowls where a tube would not fit. Both need the fish tank lid, hood or canopy in place to hold the heat in.
What else does the tank need?
A heater works with the rest of the equipment: filters and pumps move the warm water around, lighting keeps plants growing, and a thermometer confirms the temperature. Our other departments cover these aquarium supplies and accessories, from air pumps to LED lights.
Preset or adjustable?
Preset heaters hold one temperature (78°F) and need no setting. Adjustable heaters let you choose — useful for goldfish, shrimp, or treating disease.
Glass, PTC or titanium?
Glass tubes heat evenly and suit most tanks. Flat PTC heaters have no glass and suit bowls. Titanium can't break — good with large fish or turtles.
Where should the heater go?
Near the filter outflow or in the current, fully submerged, away from gravel. Keep the plug above the water and use a drip loop.
Do I need a thermometer?
Yes, a separate thermometer at the opposite end shows whether the whole tank is warm. Several DaToo heaters include one.
Maintenance
Wipe algae off the tube during water changes, unplug before your hands go in, and check the indicator light now and then: it should switch off once the water is warm. Seasonal changes matter too — in summer the heater may barely run, in winter it works harder.