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What range does Finnex publish for the TH-800S?
The TH-800S is the 800 W TH configuration with a 140–265 US-gallon manufacturer range. It is the family's largest listed option, but the lower endpoint is not optional and the current finder cannot enforce it. Its 265-gallon ceiling is not a guarantee of a specific temperature rise in a particular large aquarium.
Explore this need in the finder →What physical and electrical checks matter most for the TH-800S?
Finnex lists a 16.5-inch tube, 0.75-inch diameter, 120 V and 9.0 A on the TH-800S family row. Its separate combo table labels 9.0 A as an at-115-V figure, so check the actual nameplate and electrical instructions rather than treating the reference as settled. Confirm space for the tube and controller load before comparing an offer.
Explore this need in the finder →Can the TH-800S be used without buying a controller?
Finnex's standalone TH Shop page says the titanium tube is sold without a controller, so a compatible external temperature-control unit is a separate requirement. Finnex documents an HC-820M + TH-tube combo, but this does not make the controller part of every tube listing. Verify the exact bundle, load rating, connection and instructions.
Explore this need in the finder →The largest TH tube, with a real lower boundary
This is an evidence-based assessment of the Finnex TH-800S 800 W titanium heater element. It does not report personal ownership, a controlled test or measured temperature performance. Finnex's TH-family specification identifies the TH-800S at 120 V and 9.0 A, with a 0.75-inch diameter and 16.5-inch tube length. Its stated aquarium range is 140–265 US gallons. That is substantially larger than the TH-300S's 40–80-gallon band and the TH-500S's 70–130-gallon band, but it is not an unrestricted “up to 265” recommendation. A tank below 140 gallons would fall under Finnex's own listed lower endpoint.
The official Finnex Shop shows 800 W as one of three TH tube-only product options. Finnex's Deluxe Combo page maps the same power tier to an HC-820M combination labelled TH-0800S, whereas the current TH/THD family page calls the element TH-800S. The extra zero appears in the combo-table naming; it does not supply a separate retailer SKU or UPC. The product offer and exact identification should be matched by wattage and model marking on the unit rather than by assuming a generic title is sufficient.
What an 800-watt element does—and does not—include
Finnex calls the standalone offer a titanium heating tube only and states that controllers are sold separately. The tube therefore needs a compatible external temperature controller for a controlled aquarium setup; this assessment does not attribute a thermostat, display or setpoint range to the element. The current Shop page and the separate Deluxe Combo page are not equivalent packages: the latter is specifically presented as HC-820M plus TH tube, while the former's title and copy say the controller is a separate purchase.
Finnex says that other controllers accepting three-prong heating elements can also work. A controller should be checked for the exact plug/connection and wattage load, not selected on display features alone. The HC-820M manual is one optional controller's document, not a TH-800S manual. It lists that controller's 110–120 V input, 49.9–94°F setting range and 1000 W maximum load. Those figures do not establish what is included with the tube, and they should not be carried over to a different controller. For a high-power model, confirming the exact controller, electrical input and installation instructions is a prerequisite rather than a finishing detail.
Large tank label, long tube, and current ambiguity
At 16.5 inches, the TH-800S is the longest of the three TH models Finnex lists. The 300 W tube measures 10 inches and the 500 W tube 14 inches; each has the same stated 0.75-inch diameter. The THD family is a separate design: Finnex lists a 700 W THD-700S at 13.75 inches with a 110–200-gallon range, while the TH-800S is longer, rated at a different wattage and listed for 140–265 gallons. Those table differences matter when checking enclosure space, power draw and model identity. Neither the 700 W THD nor 800 W TH should be presented as a plug-compatible substitute without their own setup and controller instructions.
There is a small but relevant source discrepancy in electrical current basis. The current family page gives 120 V and 9.0 A in adjacent columns for TH-800S. Finnex's combo table gives the corresponding 800 W tube 9.0 A under a label that says “Amperage @115V.” I preserve the number but do not assert one amperage reference voltage. The sources reviewed here provide no frequency figure for the TH-800S. Before using any electrical value to decide on a circuit, read the actual element and controller labels and the instructions supplied with the exact package.
Guard, titanium claims, and missing installation instructions
Finnex describes titanium as a material that will not shatter like glass, says the TH series includes a high-temperature protective guard, and lists the line for both freshwater and marine aquariums. The guard is intended to limit direct contact with the hot tube, according to the manufacturer. These are useful documented features, but this review does not imply that the full assembly cannot break, that its advertised material proves longer service life, or that a cage alone makes an installation safe.
The reviewed TH pages do not identify the permitted mounting orientation, immersion line, required clearance, dry-running limits or inline-filter installation. A picture of a tube and guard cannot substitute for those instructions. The controller manual only describes the controller's technical table, while the family page's setup content is limited. Confirm the instructions for the exact element and controller package before installation; do not operate based solely on a sizing table or a cropped product photograph.
Why the TH-800S is a reference-only model here
The current finder cannot enforce the manufacturer's 140-gallon lower capacity endpoint. Activating this model would risk returning it for smaller aquariums that fall outside the published band. The second limitation is package completeness: the observed TH item is a tube-only sale, not a ready-controlled heater. The reviewed evidence does not settle exact installation or an included control system. The TH-800S remains outside ordinary finder matches and questionnaire-based purchase recommendations; its separate model-reference lookup identifies the bare-tube configuration without presenting an actionable fit recommendation or certifying a marketplace offer.
All four current official Shop images were inspected. They show the TH tube, guard and close-up details, but they do not label the TH-800S wattage or demonstrate a distinct 800 W retail package. Since the product selector offers 300, 500 and 800 W on the same page, these shared images cannot verify the particular option. No exact-model image is integrated. The Shop page also marked the wattage choices sold out at retrieval on the date checked; this does not prove the line has been discontinued or determine availability elsewhere. A potential 800 W buyer should confirm the exact TH-800S code, 140–265-gallon guidance, 16.5-inch length, controller compatibility and electrical markings directly against the current package and supplied instructions.
Key specifications
Key details at a glance
| Rated heater power | 800 W |
|---|---|
| Supported water types | freshwater / saltwater |
| Electrical supply | 120 V |
Use the exact model’s instructions for operating limits, supplied equipment and version differences.
Sources for this review
Sources for this assessment
Check the complete aquarium setup
Use the finder to compare documented tank size, water type, installation and temperature-control fit. A match does not guarantee the keeper's species-specific target or measured performance.