Finnex HMA-100s 100 W Titanium Aquarium Heater

Exact-model photograph is not verified. Text-only reference lookup. The ordinary review uses an officially associated HMA-family photo showing a heater tube, controller and guard, but it does not identify the 100 W assembly or a retail package. No exact HMA-100s package photo is verified or shown on this reference page.

Finnex's HMA-100s row pairs 100 W with a 20–30 US-gallon band; the 20-gallon floor matters because the site's finder cannot enforce it. The table also gives 0.9 A at a 115 V reference and a 68–92°F control range, but not a complete electrical rating or model-specific installation directions. This is an exact-name model lookup, not a fit recommendation.

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

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Documented model details

• The individually named HMA-100s row is 100 W, 0.9 A at the table's 115 V reference, 68–92°F control, and 20–30 US gallons. The lower endpoint is a real part of the maker's stated range, not just a maximum-capacity comparison.
• The adjacent HMA rows are separately named: HMA-50s is 50 W / 10–20 US gallons, while HMA-150s is 150 W / 30–60 US gallons. Their shared 20- and 30-gallon endpoints do not establish interchangeable output or fit.
• Finnex describes the HMA family as a titanium tube for freshwater and saltwater, with an indicator and guard with suction cups, and claims control within ±2°F of the setting. The page calls the controller analog in one place and electronic in another; that wording is not evidence of two control modes or independently verified performance.
• Finnex's sizing note limits its chart context to a standard enclosed aquarium and states maximum heating capacity of ±8°F above ambient. Room-to-water temperature difference is therefore relevant; this is not a guarantee for every tank or target temperature.
• Finnex's general warranty page states 180 days for an original purchaser under normal use and excludes dry-burn damage. It does not establish coverage for a particular HMA-100s retail item or seller offer.

Limits to weigh

• The 20–30 US-gallon range includes a 20-gallon minimum. The site's max-only volume rule cannot enforce that lower bound, so this HMA-100s reference is not shown as an ordinary finder match.
• The 0.9 A figure is explicitly tied to a 115 V reference. The reviewed sources do not give the full allowed supply-voltage range or frequency; confirm the actual unit nameplate and current exact-model instructions.
• The inspected Finnex instructions index lists other heater manuals but no HMA manual. This bounded index observation does not prove no HMA instructions exist, and setup rules from HMH or another family are not transferred.
• The model row does not provide an exact HMA-100s SKU/UPC, body length, required clearance, detailed mounting or waterline instructions, or an authenticated retail package. The bounded ten-card titanium Shop collection omits HMA only within that collection; no lifecycle or wider-availability conclusion follows.
• Analog/electronic controller wording and the ±2°F tolerance are Finnex's own descriptions; no independent accuracy or stability test, selectable increment, or model-specific package image is established.

Check before ordering

• Check that the offered heater and carton identify Finnex HMA-100s at 100 W; do not substitute HMA-50s, HMA-150s, or another Finnex heater family.
• Compare the full 20–30 US-gallon manufacturer band with the actual aquarium, and account for Finnex's stated standard-enclosed-tank and ±8°F-above-ambient context rather than relying on 30 gallons as a universal ceiling.
• Read the actual unit nameplate for permitted voltage and frequency. The chart's 0.9 A at 115 V is a reference point, not a complete supply rating.
• Obtain the current HMA-100s instructions for installation, immersion, mounting and clearances; do not borrow HMH instructions or infer a safe installation from a family photograph.
• Ask the seller to confirm the exact HMA-100s package and any item number, and verify that the return and warranty terms apply to that offer. The review has no verified retail SKU/UPC or package identity.
• Choose the livestock-appropriate water target independently of the 68–92°F controller span, and treat the ±2°F figure as a manufacturer claim rather than measured performance.