Best protein skimmer for a Waterbox AIO 20 Cube
A protein skimmer pulls dissolved organics out before they break down. Rate it for your water volume — with a little headroom for bioload.
Look for a skimmer rated to at least 16 gal (62 L), ideally ~24 gal (90 L), for the Waterbox AIO 20 Cube (62 L / 16 gal net volume). Size to how heavily you'll stock, not just gallons — bigger isn't automatically better.
Showing the 12 best-fit picks. 61 more protein skimmers in the catalog — see all protein skimmers.
Frequently asked
What's the best protein skimmer for a Waterbox AIO 20 Cube?
AquaReady HOB-1.5 is the closest fit in our catalogue — for the Waterbox AIO 20 Cube's 62 L (16 gal) you want a skimmer rated to at least that volume, ideally around 90 L (24 gal), and it has to physically clear the Waterbox AIO 20 Cube's sump or rear chamber. Both are checked here against its published dimensions.
What size skimmer for a 16-gallon reef tank?
Rated to at least 16 gal (62 L) — your display volume — and ideally around 24 gal (90 L) for a normal bioload with some headroom.
Can a skimmer be too big?
An oversized skimmer can run inefficiently on a lightly-stocked tank, but it's a much softer problem than an undersized one. Match the rating to your planned bioload, not just the tank's gallons.
In-sump or hang-on-back (HOB)?
In-sump is the norm once you have a sump — quieter and tidier. HOB skimmers suit all-in-one (AIO) tanks without a sump. Check the skimmer's footprint fits your sump's skimmer chamber.
Guidance only — sizing is a starting point; verify specs with the manufacturer before you buy.