Red Sea Reefer Skimmer Review

The Red Sea Reefer Skimmer range brings simplicity and the type of innovation to something which makes you wonder why it has never been done before.

Skimmers are notoriously touchy, given to sudden and inexplicable outbursts, spewing their contents everywhere. When you have a badly behaving protein skimmer the last thing you want is it to be even more difficult than it needs to be, like overflowing cups and difficulty dialling in.

Red Sea have addressed issues that reefers come up against regularly with their protein skimmers and produced something that quite honestly works like a reefer made it, not something that they think a reefer would like.

Red Sea Reefer Skimmer Review

Reefer Skimmer Features

The Reefer Skimmer range includes a number of well thought out features that make it a fantastic, easy to use addition to any salt water tank.

Diffusion Chamber And Pump

Red Sea describes the diffusion chamber as ‘ergonomic’. The word ergonomic means ‘designed for efficiency’ and this is no over-exaggeration.

Their efforts to manufacture a product which is indeed designed for efficiency when coupled with the PSK pump means that this protein skimmer probably produces the finest, most evenly dispersed bubbles of any skimmer on the market.

The decision to incorporate a PSK pump manufactured by an Italian company called Sicce, known for their pump quality and reliability going back decades, demonstrates Red Sea’s drive in producing quality products.

The pump itself is AC, traditionally known to be noisier than DC pumps, but equally known for their longevity over DC pumps.

Quiet Operation

The operation of the Reefer Skimmers could be described as just about silent.

I have an RSK600 running in my sump, and even with the cabinet doors open I cannot hear it, unless I lean near it and actually listen for the hum.

The reason the skimmer is so extremely quiet is due to the incorporation of ‘vibration absorbing components’ according to Red Sea’s literature.

These vibration absorbing components are actually rubber parts interfacing with the plastic body at every point where there is likely to be vibration transfer.

  • The PSK pump is mounted on a rubber quick release holder to immediately stop vibration.

  • The base plate of the skimmer is supported by four sturdy rubber feet.

  • The venturi intake is secured to the pump through the skimmer body with a rubber sleeve that fits over the pump intake. This corresponds with an o-ring mounted onto the plastic body through which the intake passes. Both ensure there is absolutely to vibration transferal between plastic components.

  • Red Sea also attribute the quiet operation to the large air intake silencer.
Red Sea Reefer Skimmer

Assembly Positions

This is where you can see some real thought has gone into the design of the Reefer Skimmer.

We all have differing sump designs, and when introducing a skimmer we need to consider it’s placement to make sure it does not interfere with things like the potential for micro bubbles to find their way into the display, or taking up dosing salts which are dosed into the same compartment.

You may have a UV steriliser mounted on the cabinet wall which prevents placement in a certain area of your sump.

The developers at Red Sea have made the Reefer Skimmer a multi-position skimmer to address the above issues.

The diffusion chamber, together with the pump inlet and regulation valve can be secured to the base plate in three different positions. This allows you to configure the skimmer in a way that specifically suits your individual setup. All it takes is undoing four screws on the base plate.

It becomes a truly individual piece of kit.

FoamVeiw™ Window

I’ll be honest, at first I thought this was just a bit of a gimmick that reduced the cup size.

I have changed my mind though, because it is another one of those things that you never knew you needed until you have it.

Simply put, part of the collection cup is indented so that it creates a ‘window’ which allows you to see the bubbles in the neck of the skimmer.

Why do I think this is a great addition?

With all other skimmers, once the collection cup gets a bit dirty you can no longer see the action of the bubbles in the neck of the skimmer, nor can you see how dirty the neck of the skimmer has become.

With this unique viewing window your view of the neck is never obscured. This enables you to monitor the bubbles at their highest point and dial the skimmer in precisely for maximum benefit, even if the collection cup is crammed.

Red Sea Foamview Window
FoamVeiw™ Window

Built-in Manual Neck Cleaner

Prior to owning this RSK600 I had never had a neck cleaner installed on any skimmer. Cleaning the neck had always been part of my weekly cleaning schedule, along with the collection cup itself.

For me personally, this built-in manual neck cleaner is a fantastic addition.

The cleaner is operated from the lid of the collection cup with a rotary ‘handle’. By turning the handle, the neck cleaner rotates within and wipes the accumulated gunge away.

The neck cleaner is simply a rectangular piece of plastic attached at the lid with a length of rubber wipers (think of windscreen wipers) running down each side. As you turn the handle, the wipers clean the neck.

Precision Geared Valve

This is another first in the world of skimmers – the Reefer Skimmer actually has a geared cog.

The geared cog can be viewed by turning the skimmer base plate upside down.

It works in conjunction with the red flow regulation knob. By turning the knob you are directly controlling the turning of the cog which in turn closes or opens a graduated flow ‘valve’.

Having used other skimmers in the past, I have always found that flow adjustment can be tiresome and more about hoping you have got the regulation right.

With this ‘precision geared valve’ I have found it to be immediately responsive. The smallest turn of the knob increases or decreases the flow precisely, and the result is much greater control of the level at which the bubbles rise to.

Dialling in for wet skimming or dry skimming has become far easier with the Reefer Skimmer. 

Drainage Port

Now my absolute favourite addition, the drainage port.

Not enough can be said about this marvel of skimmer engineering!
Yes, it is just a one metre length of hose attached to the bottom of the collection cup with a flow regulator added on the end. But what a world of difference it makes to skimmer maintenance.

In the past I have always had to remove a collection cup to remove the skimate before we have an overflow problem.
Now I only need to remove the collection cup when it is entirely necessary, which is very infrequently.
Draining the skimate is as simple as choosing your receptacle of choice, opening the flow regulator and allowing the skimate to empty from your collection cup into your receptacle.

If nothing else sells this skimmer, it will have to be this.

Not only is this good for draining skimate, but we have all had the occasion where we have treated the tank and the skimmer has gone mental. With the Reefer Skimmer you have the option of opening the valve and allowing the overflow to drain through the hose back into the sump.

No more overflowing collection cup!  

Red Sea Reefer Skimmer Sizes

The orientation of your Reefer Skimmer is determined by your assembly position.
Although there are 3 assembly positions, this equates to 2 orientation sizes as set out below.


23 x 21cm
9.1 x 8.3 in

26 x 24cm
10.2 x 9.4 in

29 x 27cm
11.4 x 10.6 in

Orientation 2

25 x 18cm
9.8 x 7.1 in

29 x 21cm
11.4 x 8.3 in

32 x 24cm
12.6 x 9.4 in


21 in

22 in

23 in

Red Sea Reefer RSK-300 Protein Skimmer
  • RSK - 300 Footprint - 9.1 x 8.3 or 9.8 x 7.1 - 21 Inches Tall
  • Rated: 80 - 240 Gallons
  • Ergonomic diffusion chamber evenly disperses the fine bubbles created by the PSK pump across the skimmer cone, without reducing air or water flow.

I was quite surprised by the size of the skimmer when it arrived, having never looked at the dimensions before ordering it.
I would suggest it it probably worth double-checking sizes to ensure the skimmer footprint is compatible with your sump design.


Red Sea have also specified a recommended sump water height per skimmer. However I have found that this specification is only a guide, as my skimmer sits slightly deeper that the recommendation.
When your skimmer arrives it will have a red water height sticker included to indicate desired water height.

Red Sea Reefer 600 Protein Skimmer
  • RSK - 600 Footprint - 10. 2" x 9. 4" or 11. 4" x 8. 3" - 22 Inches Tall
  • Rated: 160 - 500 Gallons
  • Ergonomic diffusion chamber evenly disperses the fine bubbles created by the PSK pump across the skimmer cone, without reducing air or water flow.

Recommended Water Height

16 – 20cm
6 – 8 in

18 – 20cm
7 – 8 in

20 – 24cm
8 – 9 in

Which Red Sea Reefer Skimmer do you need?

Red Sea have rated the Reefer Skimmer against the type of system you are running, or intend to run. This is a shift from skimmers being rated according to tank volume only.

SPS Coral

300L (80 Gal)

600L (160 Gal)

900L (240 Gal)

Mixed Reef

600L (160 Gal)

1200L (320 Gal)

1800L (500 Gal)

Fish Only

900L (240 Gal)

1800L (500 Gal)

2700L (740 Gal)

Does The Reefer Skimmer Raise Your ORP?

Red Sea mention briefly that this skimmer will raise the ORP in your tank.
ORP is best defined by the cleanliness of water and it’s ability to break down contaminants.

So without going too deeply into what ORP is, Red Sea is simply stating that their skimmer will help to keep your water clean and that it will contribute in the breaking down of contaminants. 

So There You Have It…

This range of skimmers are simple yet efficient. They have the feel of longevity, not only through their construction but with the inclusion of a Sicce PSK skimmer pump.

Every detail has been thought through and implemented as if a seasoned reefer had made it.

It will be a superb addition to any reef tank.  

If you are interested in comparing the Red Sea Skimmer with others, please look at at this page for more options.

Red Sea Reefer Skimmer Review