Model reference
Finnex HMH-300S 300 W Digital Titanium Aquarium Heater
Model: Finnex HMH-300S 300 W Digital Titanium Aquarium Heater (manual-defined configuration; retail SKU unverified)
The exact configuration here is HMH-300S as named in the official Finnex HMH manual, checked 2026-11-01, alongside the maker’s HMH family description. The row lists 300 W, 80–100 US gallons, 2.70 A at 115 V, 50–94°F adjustment, a 12.80-inch tube and 55/39/47-inch power/controller/sensor cords. The bounded official Shop collection and HMH search, both checked 2026-11-01, did not establish a wattage-specific Shop variant, SKU, UPC, package or current offer; full voltage/frequency input and fit are not confirmed.
This model lookup is separate from the questionnaire shortlist. It does not certify that this model meets your selected requirements.
Exact-model photograph is not verified. No wattage-specific HMH product or package photograph was verified. The official HMH family artwork and manual diagram identify a series, not this selected model or delivered package; this model-reference entry is text-only.
Finnex’s manual defines HMH-300S as 300 W for 80–100 US gallons; its 12.80-inch tube and 39-inch controller lead distinguish this size. Both gallon endpoints overlap adjacent HMH rows, and the finder cannot enforce the 80-gallon minimum, so the lookup is not a tank recommendation.
Search this model on Amazon ↗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 HMH-300S row is 300 W for 80–100 US gallons. Its 12.80-inch body is longer than HMH-200S (11.61 inches) and shorter than HMH-500S (15.55 inches); the controller lead is 39 inches, versus 35.4 and 47 inches for those neighboring rows.
- Finnex lists 2.70 A at its 115 V reference and a 50–94°F control range, adjustable in 0.1°F steps, with ±0.5°F stated display accuracy. The HMH temperature sensor is built into the tube.
- The maker describes titanium and a heater guard, and states freshwater/marine use above 150 ppm TDS. Its instructions call for full submersion, circulation around the tube and elevation of the tube-to-cord sensor junction.
Limits to weigh
- The finder cannot enforce the 80-gallon minimum. Its 80-gallon start overlaps the HMH-200S end, and its 100-gallon end overlaps the HMH-500S start; this reference does not resolve those boundaries into a fit recommendation.
- The 2.70 A value is at 115 V and does not establish the complete electrical nameplate or frequency. Exact retail SKU/UPC, full package, and individual current Shop variant were not established.
- The HMH manual states that its low-water warning is active only from 58–92°F, disabled beyond that range; it warns of continued heating if the heater is out of water outside this alert band. Do not rely on it as unrestricted dry-run protection.
- Finnex’s stated >150 ppm water condition is not in the questionnaire. A model-specific HMH-300S package photo was not verified; family artwork/manual diagrams are not exact selected-assembly photographs.
Check before ordering
- Confirm HMH-300S and 300 W on the actual offer/package; do not treat a generic Finnex titanium heater or sibling wattage as this configuration.
- Read 80–100 US gallons with both endpoints in view. The 80- and 100-gallon edges also appear on adjacent HMH rows, so do not infer a unique recommendation from a boundary match.
- Check the actual electrical label, supplied directions, seller, controller and package contents before ordering; 2.70 A at 115 V is not a full voltage/frequency rating.
- Plan for the 12.80-inch tube and the 39-inch controller lead. Follow the HMH immersion, circulation, sensor-position, GFCI/drip-loop and maintenance directions, including the >150 ppm TDS and 58–92°F warning constraints.