Finnex THH-800S 800 W Titanium Heater Tube

Exact-model photograph is not verified. Text-only reference: no exact THH-800S wattage/package photograph is verified. The source review retains an official THH-family appearance image with an explicit family-only caption; it does not show the selected 800 W package.

Finnex lists the THH-800S as an 800 W titanium tube for 140–265 US gallons, with a 17.32-inch tube. It requires a separate temperature controller and water above 150 ppm TDS; because the finder cannot enforce the 140-gallon minimum or verify a complete controller setup, this is an identification reference—not a tank-fit match.

Search results may include other models. Confirm the exact model, applicable region, condition and included parts before ordering.

As an Amazon Associate I earn from qualifying purchases.

Read the detailed model assessment · Find products for my needs

Documented model details

• The exact THH-800S row is 800 W, 9.0 A at a stated 115 V reference, and 140–265 US gallons; the table lists a 17.32-inch tube. The shorter THH-300S and THH-500S rows are 10.63 and 14.57 inches, respectively, so the three size configurations are not interchangeable for clearance.
• The same row separately reports a 6-inch “Power Cord” and a 70-inch controller-to-heater cord. The first value is unusually short and its routing definition is not clear enough to treat as a wall-to-tube cable length; verify both against the exact package.
• Finnex says a THH tube must use an external temperature-control unit and must not be plugged straight into a wall outlet. The out-of-water sensor cuts heater power when the tube is exposed; that safety feature does not independently regulate an aquarium setpoint.
• Finnex names freshwater and marine use but requires water with TDS above 150 ppm. It places the sensor where the element meets the cord and calls for that point to sit higher than the rest of the heater, with sensor cleaning and function checks every 30 days.
• Finnex lists a protective heater guard and describes the titanium element as corrosion resistant. Those are separate from a substantiated shatterproof-body claim; none is treated here as proof of impact resistance or permission for dry operation.

Limits to weigh

• The 140-gallon lower endpoint is meaningful, but the finder’s volume rule only checks a maximum. The THH-800S therefore remains excluded from matches rather than being recommended for every tank up to 265 gallons.
• The heater tube requires separate temperature control. The saved retailer page identifies the THH tube with no controller included and shows no selectable options; the reviewed source set does not establish a current exact offer, compatible controller package or controller setpoint range.
• The table’s 9.0 A at 115 V is not a complete unit nameplate. Full voltage/frequency, retail SKU/UPC and current product/package identity remain unverified.
• The reviewed manufacturer instruction index has no THH entry. Exact immersion depth, orientation, clearances and permission for dry operation remain unknown; an out-of-water cutoff is not installation guidance.
• The six-inch power-cord field needs package-level clarification, and the exact THH-800S photo remains unverified. A shared THH-family visual does not identify the 800 W package.
• The finder cannot ask for the strict above-150-ppm TDS condition. A freshwater or saltwater choice alone does not clear that separate manufacturer requirement.

Check before ordering

• Check that the selected tube and package say Finnex THH-800S / 800 W; do not substitute THH-500S, THH-300S, TH-800S or THD-700S. Confirm whether a separate controller is included and its supported load, sensor arrangement and setting range.
• Read the actual unit’s full electrical nameplate and controller instructions. The table’s 9.0 A at a 115 V reference is not a complete input rating, and Finnex explicitly says not to connect the tube directly to a wall outlet.
• Check that the actual aquarium water meets Finnex’s above-150-ppm TDS condition; broad freshwater/marine classification is not enough. The published volume band is 140–265 US gallons, not a guarantee for a particular room or heat-loss condition.
• Obtain model-specific installation instructions before mounting. Confirm immersion/orientation requirements and follow Finnex’s sensor-positioning, 30-day check and cleaning guidance; do not use the cutoff as permission to run dry.
• Measure the 17.32-inch tube against available placement space and confirm cable routing. Ask the seller or inspect the package to clarify the unusual six-inch power-cord field and the separate 70-inch controller-to-heater lead.