# Waterpik Aquarius WP-660 vs h2ofloss HF-9: specs and price compared

A sourced, side-by-side comparison of the Waterpik Aquarius WP-660 (Waterpik) and h2ofloss HF-9 (h2ofloss) among water flossers. h2ofloss HF-9 is the cheaper of the two at $43.9.

## Side by side

| Spec | Waterpik Aquarius WP-660 | h2ofloss HF-9 |
| --- | --- | --- |
| US price | $99.99 | $43.9 |
| Brand | Waterpik | h2ofloss |
| Released | 2013 | — |
| Type | countertop | countertop |
| Tank capacity (ml) | 651 | 800 |
| Pressure settings | 10 | 5 |
| Max pressure (psi) | 100 | 110 |
| Tips included | 7 | 13 |
| Power | corded | corded |
| Runtime min | 1.5 | — |

## Key differences

- Tank capacity (ml): Waterpik Aquarius WP-660 651 vs h2ofloss HF-9 800
- Pressure settings: Waterpik Aquarius WP-660 10 vs h2ofloss HF-9 5
- Max pressure (psi): Waterpik Aquarius WP-660 100 vs h2ofloss HF-9 110
- Tips included: Waterpik Aquarius WP-660 7 vs h2ofloss HF-9 13

## Sources

- Waterpik Aquarius WP-660: https://www.waterpik.com/products/dental-water-flosser/WP-660/ (waterpik.com, verified 2026-06-19)
- h2ofloss HF-9: https://h2ofloss.com/products/hf-9 (h2ofloss.com, verified 2026-06-19)

Canonical: https://frontdeskreview.com/gear/water-flossers/waterpik-aquarius-wp-660-vs-h2ofloss-hf-9/
Cite: Per The Front Desk Review, Waterpik Aquarius WP-660 ($99.99) vs h2ofloss HF-9 ($43.9) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/water-flossers/waterpik-aquarius-wp-660-vs-h2ofloss-hf-9/
License: CC BY 4.0.