Quick answer
The Aquastrong HEX035 (35,000 BTU, 115V inverter, $1,199 on Aquastrong’s own PRO listing as of October 29, 2026) is the model to buy for most above-ground and small in-ground pools up to about 7,000 gallons. Size it from the cold-weather spec, not the box: Aquastrong’s own owner’s manual shows the HEX035 delivering 23,900 BTU at 59°F air, about 68% of its 35,000 BTU nameplate, and its “15.8 COP” headline is the minimum-speed figure. At full output the manual lists 6.8. For a bigger pool, the 220V HEX075 ($1,999) is the best value per BTU in the lineup and costs $200 less than the smaller HEX055. Register within 90 days: the inverter manual’s base warranty is one year, not the three years the listings advertise.
Aquastrong is a direct-to-consumer pump brand (pool pumps, sump pumps, well pumps) that sells its pool heat pumps on aquastrong.co and Amazon. It is not in the same tier as the dealer brands in our pool heater brands guide, and it doesn’t try to be: the pitch is plug-in installation and a price well below Hayward or Pentair. Everything below comes from Aquastrong’s own store listings and the owner’s manuals it hosts on its support page, checked October 29, 2026.
Aquastrong pool heat pumps at a glance
Aquastrong sells three families: MINI (small 115V units for pools up to 6,500 gallons), PRO (full-inverter 115V and 220V units, 22,000-100,000 BTU), and the newer TOP discharge line (fan on top instead of the side, launched in 2026). The 59°F column is the one to size from:
| Model | Family | BTU at 80°F air | BTU at 59°F air | Power | Advised pool (with cover) | Price (aquastrong.co, Oct 29) |
|---|---|---|---|---|---|---|
| HEX016 | MINI | 16,000 | 10,440 | 115V / 11.9 A | 5,000 gal | $699 |
| HEX018 | MINI | 18,000 | 11,672 | 115V / 12.6 A | 6,500 gal | $649-$799 |
| HEX035 | PRO (inverter) | 35,000 | 23,900 | 115V / 18 A | 9,000 gal | $1,199-$1,499 |
| HEX055 | PRO (inverter) | 55,000 | 45,000 | 220V / 14.5 A | 16,000 gal | $2,199 |
| HEX075 | PRO (inverter) | 75,000 | 67,600 | 220V / 23 A | 21,000 gal | $1,999-$2,499 |
| HEX100 | PRO (inverter) | 100,000 | 76,800 | 220V / 30 A | 26,000 gal | $2,634-$3,099 |
| HEX035TOP | TOP (inverter) | 39,000 | 31,732 | 115V / 18 A | 9,000 gal | $1,999 |
BTU and amperage figures come from the spec tables in Aquastrong’s HEX012/016/018, HEX022-HEX100, and HEX022TOP/HEX035TOP owner’s manuals. Where two prices are shown, Aquastrong listed the same model at two prices on its own store (more on that below). The 12,000 BTU HEX012 and the PRO-series HEX022 were marked sold out. A separate 22,000 BTU “HEX022MINI” was listed at $799-$899, and the larger TOP units (80,000-140,000 BTU) ran $2,999-$3,699.
What “35,000 BTU” and “15.8 COP” actually mean
Every Aquastrong headline number is measured at 80°F air, 80°F water, and 80% humidity, which is warm, humid summer weather. The HEX035 manual’s own spec table shows what happens on a cool spring evening:
| HEX035 spec (owner's manual) | 80°F air / 80°F water / 80% RH | 59°F air / 80°F water / 70% RH |
|---|---|---|
| Heating capacity (max / min) | 35,000 / 7,850 BTU/h | 23,900 / 6,480 BTU/h |
| COP range | 6.8-15.8 | 4.17-7.6 |
| Noise | 48 dB at 33 ft / 62 dB at 3 ft | Same rating |
The 15.8 COP figure on the product listing is the top of that first range. An inverter is most efficient when it’s barely running, near its 7,850 BTU minimum. When the pool is cold and you need the full 35,000 BTU, the manual’s own COP is 6.8. For comparison, the Hayward HeatPro and Pentair UltraTemp publish a single AHRI-rated COP of 5.7 and up to 5.8 on their 140,000 BTU units (see our best pool heat pump rankings). Neither Aquastrong’s listings nor its manuals cite an AHRI certificate, so treat its figures as manufacturer-stated.
The noise rating works the same way. Listings say “just 48 dB”, and the manual shows that’s measured at 33 feet. At 3 feet the same unit is rated 62 dB.
The gallon ratings are also optimistic. Aquastrong’s “advised pool volume” assumes a pool cover and works out to roughly 3 to 3.9 BTU per gallon. This site’s usual starting point is 5 BTU per gallon (see our pool heater sizing chart), which puts the HEX035 at about 7,000 gallons rather than 9,000, and the HEX018 at about 3,600 gallons rather than 6,500.
1. Aquastrong HEX035 — Best Overall
Aquastrong HEX035 PRO Inverter Heat Pump (35,000 BTU, 115V)
- The largest 115V unit in the PRO line: 35,000 BTU at 80°F air and 23,900 BTU at 59°F, per Aquastrong's own manual. That is enough for a typical 15-18 ft round above-ground pool with a cover.
- Full DC inverter with heat, cool, and auto modes, app control through the Tuya Smart app (2.4 GHz Wi-Fi or Bluetooth), and an operating range down to 5°F air.
- It draws 18 A, which is more than a typical 15-amp outlet circuit is rated for, so "plug and play" still needs a suitable dedicated circuit.
- On October 29 it cost $1,199 on Aquastrong's multi-size PRO listing and $1,499 on its own single-model page, for the same HEX035.
- Aquastrong's own store shows 4.7/5 from 345 reviews on the single-model page. That's a brand-run widget, not an independent review platform.
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The HEX035 is where Aquastrong’s pricing makes the most sense. It sits within $100 of FibroPool’s 35,000 BTU FH135 ($1,299.99 on fibropool.com), adds a full inverter and app control, and still runs on 115V. Just size it as a 7,000-gallon heater, keep a cover on the pool, and expect slow progress on cold nights. Our above-ground pool heater guide covers the 240V alternatives if your pool is bigger than that.
2. Aquastrong HEX018 (MINI) — Best Budget Pick for Small Pools
Aquastrong HEX018 MINI Heat Pump (18,000 BTU, 115V)
- The cheapest way into a real heat pump: $649 on the MINI listing on October 29, which was $50 less than the smaller HEX016 at $699.
- The manual lists one fixed COP for each test condition (5.5 at 80°F, 4.06 at 59°F) rather than an inverter range, even though the MINI listing title says "Inverter". Expect it to cycle on and off rather than modulate.
- The single-model page claimed a 6.5 COP, while the MINI listing and the manual both say 5.5. Go by the manual.
- Aquastrong's own heating-rate table for the MINI line caps water at 77°F for a 5,300-7,900 gallon pool in 53-59°F weather, and 86°F only for pools under 2,600 gallons.
- The MINI manual has the better warranty in the lineup: two years, extended to three with registration within 90 days.
The HEX018 is the right buy for a soft-side or 12-15 ft above-ground pool, a stock tank, or a small cocktail pool. Above about 4,000 gallons it’s undersized for anything but warm-weather topping up. Our small pool heater guide compares it against FibroPool’s 120V FH120.
3. Aquastrong HEX075 — Best Value for Larger Pools (220V)
Aquastrong HEX075 PRO Inverter Heat Pump (75,000 BTU, 220V)
- It loses the least output in cool air of any PRO model: 67,600 BTU at 59°F, about 90% of its 75,000 BTU rating, per the manual's spec table.
- At $1,999 on the PRO listing it works out to about $30 per 1,000 BTU of 59°F output, the lowest in the lineup. The HEX035 is about $50 and the HEX055 about $49.
- Skip the HEX055: at $2,199 it costs $200 more than the HEX075 on the same listing and delivers 22,600 fewer BTU at 59°F.
- It weighs 194 lb and must be hardwired to 220V, with an #8 AWG bare copper bonding wire to a ground rod per the manual. Budget for an electrician.
For a large above-ground pool or a small in-ground pool, the HEX075 undercuts FibroPool’s 70,000 BTU FH270 ($1,999.99) on price per BTU only when you buy from the cheaper PRO listing. At $2,499 on the single-model page, the FibroPool is the better deal. The 100,000 BTU HEX100 has an oddity in its manual: the spec table lists a 30 A current draw, while the same manual’s power-supply table specifies AWG12 wiring for all three 220V models, a wire gauge normally paired with a 20 A breaker in US practice. Have your electrician size that circuit from the unit’s data plate.
4. Aquastrong HEX035TOP — Best for Spring and Fall Heating
Aquastrong HEX035TOP Top-Discharge Inverter Heat Pump (39,000 BTU, 115V)
- It holds output in cool air far better than the side-fan HEX035: 31,732 BTU at 59°F versus 23,900 BTU, or 33% more heat in the conditions where you'll actually use it, per the two manuals.
- Its manual lists a single 5.7 COP at 59°F, versus a 4.17-7.6 range on the HEX035, and a quieter rating: 34 dB at 33 ft and 50 dB at 3 ft.
- The top-discharge fan suits tight side yards. The TOP manual asks for 24 inches on all sides and 36 inches in front.
- The trade-off: its operating range stops at 41°F air, where the PRO line goes down to 5°F. It costs $800 more than the HEX035 on the cheaper PRO listing.
If you mostly heat in April-May and September-October, the HEX035TOP’s cold-air output is worth more than the PRO model’s lower price. If you want to run the heater into late fall below 41°F, it won’t, and a gas heater is the better tool for that job anyway. See our gas vs. heat pump comparison.
The warranty: three different numbers
This is the biggest gap between Aquastrong’s marketing and its paperwork. On October 29, 2026, the terms read:
| Source | What it says |
|---|---|
| Product listings (MINI, PRO, TOP) | "3-year warranty" |
| Inverter (PRO) manual, cover | "24 months limited warranty" badge |
| Inverter (PRO) manual, warranty page | One-year limited warranty from purchase; extended to two years if registered on Aquastrong's website within 90 days of delivery |
| MINI manual (HEX012/016/018) | Two-year limited warranty; extended to three years with registration within 90 days |
| Register Warranty page | Registration adds a "one-year extended warranty" |
| Conditions (both manuals) | Original purchaser only, non-transferable; excludes commercial and rental use; liability capped at the purchase price |
The only route to three years in Aquastrong’s own documents is buying a MINI model and registering it within 90 days. For the inverter models, the manual’s ceiling is two years. Registrations after 90 days “will be considered invalid”, so register the day it arrives and save a screenshot of the listing’s warranty claim. For context, Pentair backs its Gulfstream heat pumps with 2 years of parts and labor plus a 7-year parts-only term (see our Gulfstream guide). Our pool heater warranty guide covers what the major brands include.
Same model, two prices on aquastrong.co
Aquastrong sells each model both on a multi-size family listing and on its own single-model page, and on October 29 the two didn’t match:
| Model | Family listing (MINI / PRO) | Single-model listing | Difference |
|---|---|---|---|
| HEX018 | $649 | $799 | $150 |
| HEX035 | $1,199 | $1,499 | $300 |
| HEX075 | $1,999 | $2,499 | $500 |
| HEX100 | $2,634 | $3,099 | $465 |
| HEX055 | $2,199 | $2,199 | None |
Before you buy anywhere, including Amazon, check both Aquastrong listings for your model. Direct-to-consumer prices move often, so treat these as a snapshot rather than fixed list prices.
Aquastrong vs. FibroPool
FibroPool is the closest established competitor: same plug-in, above-ground-friendly category, but a longer track record. Prices from both brands’ own stores on October 29, 2026:
| Size class | Aquastrong | FibroPool | Brand's gallon rating |
|---|---|---|---|
| 16,000-20,000 BTU, 115/120V | HEX016, $699 | FH120, $1,299.99 (new out of stock; refurbished $999.99) | 5,000 gal both |
| 35,000 BTU, 115/120V | HEX035, $1,199-$1,499 (inverter) | FH135, $1,299.99 | 9,000 gal (with cover) vs. 7,500 gal |
| 55,000 BTU, 220/240V | HEX055, $2,199 (inverter) | FH255, $1,799.99 | 16,000 gal (with cover) vs. 10,000 gal |
| 70,000-75,000 BTU, 220/240V | HEX075, $1,999-$2,499 (inverter) | FH270, $1,999.99 | 21,000 gal (with cover) vs. 15,000 gal in-ground |
The pattern: Aquastrong wins clearly at the small end (the HEX016 costs about half as much as a new FH120) and adds inverter control at mid sizes for similar money. Its gallon ratings are consistently more generous than FibroPool’s for the same BTU class. At 55,000 BTU, FibroPool is $400 cheaper.
Installation notes from the manuals
- Circulation: Aquastrong heat pumps use your existing pool pump. The PRO manual says a bypass isn’t needed on above-ground pools with a small pump, but recommends one on 1.5 hp-plus systems with 2-inch plumbing. Our bypass kit guide covers the parts.
- Placement: The PRO manual sets a maximum of 32.8 ft of distance between pool and heat pump, at least 59 inches clear in front, and 20 inches at the sides and back. The MINI manual asks for at least 6.5 ft from the pool. Local setback and noise rules apply too (see our setback requirements guide).
- Electrical: The 115V models use a GFCI (RCD) plug. The 220V models are hardwired, and the PRO manual calls for #8 AWG bare copper bonding to a ground rod. The manual’s electrical page also uses European terms (“30mA differential switch”, “D-curve circuit breaker”) that don’t map one-to-one onto US breakers. That’s one more reason to hire a licensed electrician and check our electrical requirements guide.
- Freeze behavior: Below 41°F air, the PRO units’ frost protection runs the circulation pump for 3 minutes every 10 minutes. For the off-season, follow our winterizing guide.
Who should buy an Aquastrong (and who shouldn’t)
Buy one if you have an above-ground or small in-ground pool, want heat-pump running costs without paying Hayward or Pentair prices, can keep a cover on the pool, and are comfortable handling warranty claims by email ([email protected]) rather than through a local dealer. Skip it if your pool is over about 15,000 gallons and you want to heat in cold shoulder-season weather, if you need a dealer who can come out and fix it, or if you want an AHRI-listed efficiency rating. In those cases, look at the best inground pool heater picks instead.
The bottom line
Aquastrong’s heat pumps are a real budget option, but read the spec sheet before the headline. The HEX035 is the best all-round buy for pools up to about 7,000 gallons, especially at the $1,199 PRO-listing price. The HEX018 is the cheapest real heat pump for small pools, and the HEX075 is the best value per BTU if you have 220V. The HEX035TOP is worth its premium if you mostly heat in spring and fall. Whatever you buy, size it from the 59°F row of the manual’s spec table, check both Aquastrong listings for the lower price, and register within 90 days, because the inverter manual’s base warranty is one year. For how Aquastrong compares to every other heat pump on this site, see our best pool heat pump rankings, and for brands with a dealer network, see our pool heater brands guide.