Review: REEF-Skim 500 protein skimmer from TMC


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The new REEF-Skim range from TMC ticks a lot of boxes on the' must-have' features list. Dave Wolfenden sees how the 500 model performs.

Cone-shaped body to concentrate the skimmate? Check. Bubble diffuser plate? Yes. Uber-trendy white plastic? Got it. These new REEF-Skim protein skimmers from TMC certainly look the part.

What’s in the box?

Build quality is great, with nice, thick acrylic and a chunky feel; no shoddy workmanship or rough edges. The collection cup seals satisfyingly in place with an ‘O’-ring, meaning no leaks, and the cup also incorporates a decent drain. Should you opt for wet skimming, you’ll be

grateful of this, and a drain hose is also included. Simply remove the rubber bung and hook up the hose.

The pump, which handles both air injection and water flow, is made by Sicce, so you know you’re getting a decent brand. There’s a choice of AC or DC (low voltage) pump, each with a needle wheel impeller. The DC models are slightly more expensive, although they offer controllability and a ‘feed mode’, temporarily ramping down the pump during feeding, before returning to its previous settings. The AC pumps are either on or off. On top of the pump sits the bubble diffuser, and the skimmer body shrouds these. The adjustable outlet sits on one side of the skimmer, along with an air silencer.

The pump is positioned within the lower portion of the body, so the skimmer is compact with a pretty small footprint. The base measures 15 x 15cm/6 x 6in, but allow 20cm/8in either side for pipework. It’s 45cm/18in in height, but you’ll need an additional 5cm/2in or so for removing the cup.

The REEF-Skim 500 is intended as an in-sump model only, incidentally — it’s not suitable for use in the main tank or for ‘hang-on’ mode.

Setting up

The skimmer is neatly packaged in a compact box. To be honest, it’s a bit of a faff to put together — you’ll need to partially dismantle, and then fully assemble, the unit. Still, it does mean you know how to strip it down for maintenance.

Although the assembly instructions could be better, the instructions for use are clear, with a guide to running in either 'wet' or 'dry' skimming modes, where to install it in the sump, how to rig it up with ozone, plus a troubleshooting section.

In use

A constant water depth is required for optimal use — for the REEF-Skim 500, that’s 18.5cm/7.4in, marked on the outlet pipe. Deviations due to evaporation or big top-ups can send skimmate production out of whack, and you might need to place the skimmer on something to achieve the correct level if the water’s too deep in your sump.

Allow the skimmer to run in for a day or so before fine-tuning, and keep an eye on it even after this, making tweaks when necessary — something that’s recommended for any skimmer. Then you can start making the necessary adjustments to suit your needs. Two things will help you do this. The first is that you can adjust the amount of air entering the Venturi. The second comes courtesy of the chunky blue water level adjustment dial. Twiddle this, and you’ll adjust the outlet from the skimmer, raising or lowering the water level in the body, to achieve perfect skimmate consistency.

The pump is extremely quiet, as is the Venturi itself. The foam production on my model was impressive. The diffuser plate does seem to help with creating a dense mass of bubbles in the body, maximising the efficiency of the unit. The amount of microbubbles exiting the skimmer was minimal and the microbubbles in the outflowing water had mostly disappeared once the skimmer had run in.

Cleaning and maintenance are straightforward; I did find that the vigorous bubble production allows some skimmate to froth out of the collection cup’s lid, and that white plastic really shows up the dirt! This isn’t a problem, but extra scrubbing will be needed to keep the skimmer looking tip-top.


The REEF-Skim models bring TMC’s skimmer range bang up to date, and I was impressed with the performance of the 500. The adjustability means plenty of fine-tuning is possible, and its compact, space-saving design is a big plus. It’s not cheap, but the price reflects its build quality and feature-packed nature.

Ease of use: 4/5

Features: 5/5

Value for money: 4/5

Overall score: 4.5/5

Price: RRP £169.99 (AC model), £189.99 (DC model). Other sizes available, for systems from 50–2000 l/11–444 gal.