15% off plus free shipping on your $49 order
Hydor THEO (UL) Submersible Aquarium Heater

Hydor THEO (UL) Submersible Aquarium Heater – High Quality Fish Tank Water Heater and Aquarium Water Heater Selection

Keep your aquarium at the perfect temperature with the Hydor THEO (UL) Submersible Aquarium Heater. This sleek fish tank water heater is easy to use and install. Orient your aquarium water heater either vertically or horizontally depending on your needs or preferences.

The graduated scale clicks as you dial in to your desired setting, letting you control your water temperature with ease. Choose an ideal temperature between 68-91°F; the Hydor THEO fish tank water heater will maintain your tank’s temperature to within +/- 1°F of what you set.

The Hydor THEO (UL) Submersible Aquarium Heater uses PTC patented thermal technology, making it one of the safest heating units around. The PTC (Positive Thermal Coefficient) heating element prevents this heater from building up excessive heat if run dry, eliminating the risk of breaking the glass tube. Instead, if the thermostat senses an increase in heat, the aquarium water heater will automatically shut off. Moreover, the glass used in this fish tank water heater is designed to be both shatter-resistant and shock-resistant.

No accessories are required to safely and properly use this aquarium water heater. The Hydor THEO (UL) Submersible Aquarium Heater comes with suction cups for secure placement and a 6 foot power cord. The Hydor THEO fish tank water heater is approved for use by Underwriters Laboratories, a firm approved for safety testing by the Occupational Safety and Health Administration (OSHA).

The Hydor THEO can be used in freshwater, marine and tropical aquariums. An external thermometer (sold separately) is recommended to help you monitor the actual temperature of your tank water.

Hydor THEO (UL) Submersible Aquarium Heater

Internet Price: $25.99 - $42.99   Today's Price: $20.79 - $42.99  (Save up to 20%)

Shop All Products By Hydor

  • Patented PTC heating system guarantees safe operation
  • Fish tank water heater suitable for freshwater, marine and tropical aquariums
  • Made from specially engineered shatterproof glass
  • Highly accurate micro-switch technology keeps temperature to within +/- 1°F
  • May be vertical or horizontal – suction cups secure the aquarium water heater's position in your tank
  • Completely submersible unit – power cord measures 6 feet in length

Shipping Usually Leaves Warehouse in 5-7 Business Days | More Shipping Info



For Aquariums 2-7 gallons
Model: THEO 25W
25 Watts
SKU: 1491296

ONLINE EXCLUSIVE
$25.99
Qty:

For Aquariums 5-14 gallons
Model: THEO 50W
50 Watts
SKU: 1491326

ONLINE EXCLUSIVE
$25.99 $20.79
Qty:

For Aquariums 14-26 gallons
Model: THEO 100W
100 Watts
SKU: 1491229

ONLINE EXCLUSIVE
$28.99 $23.19
Qty:

For Aquariums 23-40 gallons
Model: THEO 150W
150 Watts
SKU: 1491334

ONLINE EXCLUSIVE
$34.99
Qty:

For Aquariums 26-53 gallons
Model: THEO 200W
200 Watts
SKU: 1491300

ONLINE EXCLUSIVE
$36.99 $29.59
Qty:

For Aquariums 53-80 gallons
Model: THEO 300W
300 Watts
SKU: 1491342

ONLINE EXCLUSIVE
$39.99
Qty:

For Aquariums 80-105 gallons
Model: THEO 400W
400 Watts
SKU: 1491318

ONLINE EXCLUSIVE
$42.99
Qty:


SEE HOW THESE PRODUCTS COMPARE Easy Returns to Store | Safe Shopping

ADD TO MY SHOPPING LIST


YOUR PET MIGHT ALSO LIKE
Aqueon QuietFlow Replacement Filter Cartridges

Aqueon QuietFlow Replacement Filter...

$8.79 to $35.99
Up to 20% off

Aqueon Submersible Aquarium Heaters

Aqueon Submersible Aquarium Heaters

$27.99 to $39.99
Up to 20% off

Aqueon Pro Heaters Submersible Aquarium Heaters

Aqueon Pro Heaters Submersible Aquarium...

$30.39 to $47.99
Up to 20% off

Tetra Submersible Aquarium Heaters

Tetra Submersible Aquarium Heaters

$14.99 to $18.99
Up to 16% off

Sera Aquarium Heater

Sera Aquarium Heater

$34.99 to $42.99