Aquastrong Smart 45
An all-in-one inverter booster sold direct by Aquastrong for a house on weak city pressure. A cheaper alternative to a SCALA2 if you accept a louder pump.
Amazon $711$711
The Aquastrong Smart 45 is the better water pressure booster pump overall, rated 3.6 to 3.0. The Grundfos SCALA2 3-45 115V wins on noise. The Aquastrong Smart 45 costs $168 less ($711 vs $879).
Grundfos SCALA2 3-45 115V
#12 in Variable speedFull review
The benchmark compact inverter booster for a house of up to three floors and eight taps on weak city pressure. Pay for it when quiet running and steady showers matter more than price.
Amazon $879$879
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Grundfos SCALA2 3-45 115V for noise (47 dBA vs 55 dBA).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every variable speed water pressure booster pump; a clear win is highlighted. How we rank explains each one.
| Factor weight | Aquastrong Smart 45 | Grundfos SCALA2 3-45 115V |
|---|---|---|
| Overall rating | 3.6/5 | 3.0/5 |
| Value 30% | 37 $28.44 per gpm ($711, 25 gpm) | 0 $66.59 per gpm ($879, 13.2 gpm rated; maximum not published) |
| Flow 15% | 77 25 gpm maximum | 24 13.2 gpm rated; maximum not published |
| Pressure 15% | 75 150 ft maximum head (about 65 psi) | 73 148 ft maximum head (about 64 psi) |
| Protection 10% | 100 dry-run and overheat protection | 100 dry-run and overheat protection |
| Noise 10% | 60 55 dBA | 92 47 dBA |
| Warranty 20% | 50 warranty not published (neutral score used) | 50 2-year warranty |
Specifications
| Aquastrong Smart 45 | Grundfos SCALA2 3-45 115V | |
|---|---|---|
| Pumping | ||
| Drive | Variable speed | Variable speed |
| Maximum flow | 25 gpm | - |
| Maximum head | 150 ft (65 psi) | 148 ft (64 psi) |
| Highest inlet pressure | - | 87 psi |
| Input power | 550 W | 560 W |
| Ports | - | 1 in |
| Protection and build | ||
| Built-in tank | Yes | Yes |
| Dry-run protection | Yes | Yes |
| Overheat protection | Yes | Yes |
| Outdoor rated | - | Yes |
| Voltage | 120 V | 120 V |
| Noise | 55 dBA | 47 dBA |
| Weight | - | 22 lb |
| Warranty | - | 2 years |