Barr Aquatic Systems

Super-Size Skimmers:

Now with 3D printed injectors! More water flow without the need to reduce the airflow to generate the best bubbles.

SK4020 SK4220 SK5020 SK5220 Beckett Protein Skimmers

On Backorder! Standard features include:

  • twist-lock flange instead of the thumbscrews for the collection cup.
  • Integral air filter and silencer.
  • Redesigned injector holder.
  • Ozone port on injector is standard (comes with a plug if not used).
  • CO2 port on base is standard (For the Calcium reactor effluent, comes with a plug if not used).
  • Redesigned bubble path for more contact time.
  • "Skimmer in a skimmer" mixing box for great mixing and lower bubble escape
  • Bubble diffuser plate for better dispersion
  • Four Mounting points for dual air flow meters (optiona).

These skimmers are custom designed for a greatly increased contact time. The SK5220 has over 100 inches of air-water contact time for superior stripping of organics from the water. Many other skimmers attempt to get by with a contact length of less than 12". This design will pull out more organics per pass of water though than designs with short contact paths.

The two primary models utilize a single Beckett injector which allows them to use a smaller pump, (and less electricity), yet due to the unique design the performance is excellent! Each of the primary models can be expanded with a second injector tube. The second tube make them in to "Dual Beckett" systems and are optimized for larger systems or for the quickest response to organic load changes (for example with commercial accounts that get in large fish shipments weekly).

The Beckett injector design creates a tremendous amount of foam by using an advanced venturi effect that is more powerful than any other venturi. This mixture of air and water is driven down the large diameter mixing tubes, though the unique baffles structure in the box and back up the main tube via a central 5" mixing chamber, which feeds a 4" deep-injection port topped with a dispersion plate. This tube is coaxially located within the main tube and extends up in to the main tube to force the air/water mixture deep in to the central column for an extremely long contact time. This gives a smoother transition, reduces disruptive turbulence and also greatly reduces the bubbles that the skimmer outputs though the gate valve. Note that "swirling" is neither necessary nor desired (See here).

The unique baffle system internal to the box virtually eliminates the disruptive "burping" of air that many competing skimmers have.

Easy Maintenance- Twist lock flanges can be removed with a simple 15 degree turn, and are at all key points on the skimmer- Collection cup lid, neck and injection chamber (3 total). Key holes, thumb screws and captive O-rings are used on joints that are not normally taken apart for cleaning. No removing the pump line just to clean the cup! The pump does not even need to be shut down. Simply open the gate valve a full turn (or turn off the air valve), then remove the twist lock for cleaning. Replace the top and re-set the gate valve as before and you are done.

Easy to adjust. The high quality gate valve along with the John Guest ball valves allow precise adjustment. Dialing it in for high performance is quick and easy. The optional flow meters give you instant feed back as well, letting you keep track over time of how the skimmer is performing. They also give you an instant check of the skimmer- Low air flow indicates maintenance is needed on the pump or the injectors.

Suitable for larger systems or commercial accounts. Excellent for "fish rooms" and multi-tank systems. The Dual Injector designs will react faster to large changes in bio load, but require more pumping power. An Iwaki 100 or Sequence 5000 series is ideal for the duals, and an Iwaki 55 or Sequence 4600 is great for the singles. If you are in the 1000+ gallon range, it may be best to use dual Iwaki 70's, or a large Sequence pump.


  • Capacity: 100-1500+ gallons total water volume.
  • Unique internal baffle system for better performance.
  • Twist-lock flanges, Key hole flanges, O-Ring seals.
  • Large, clear input tubes give more contact time and a view of the action.
  • 1" FNPT input with hose barb included.
  • 1.5" SCH80 Gate valve for ultra-fine water level control.
  • 1/4" Air inlet valve for precise air control to each Beckett injector.
  • 1/2" I.D. Hose barb for collection cup (collection container or bucket required).
  • No Bio-balls that need to be cleaned.
  • Clear air-tight Beckett injector housings for easy inspection and the best performance.
  • Heavy duty Cast acrylic and SCH80 PVC for a extremely long life.
  • Removable input tubes: Allows for easy changes and expansions.


  • SK4020: 36" high x 13" x 10" (100-300 gallon systems)
  • SK4220: 36" high x 13" x 10", dual Beckett (200-500 gallon systems)
  • SK5020: 48" high x 13" x 10" (100-450 gallon systems)
  • SK5220: 48" high x 13" x 10", dual Beckett (200-600+ gallon systems)

Skimmer ratings depend on your bio load and how the skimmer is plumbed. Please contact us to help you pick a skimmer size that matches your system and growth plans.


  • The SK4020 and SK5020 require a pump that can put out 600-800 GPH at 12' of head, such as a Little Giant 4MDSC or an Iwaki 55. A Sequence 4600 works great too (1/8 hp, 750 frame motor).
  • The SK4220 and SK5220 do best with a stronger pump that can put out at least 800 GPH per Beckett (1600 GPH at 12' head minimum).


  • Single flow meter kit (SK4020 and SK5020) and mounting bracket, 0-50 SCFH: $50
  • Dual air flow meter kit (SK4220 and SK5220) and mounting brackets, 0-50 SCFH each: $90
  • Second injector column for SK4020: $190
  • Second injector column for SK5020: $220
  • 12" extension for main tube (Any model, more than one can be added): $90
  • Banjo Quick Disconnect pair with fittings: $75

The water level inside the skimmer depends on the water flow though the unit, the water level at the exit point, and how wet you want the skimmate. For most internal or external installations, try to have the water level at the output the gate valve:

  • SK4220: Lower than 18", allowing 13" of pure foam space.
  • SK5220: Lower than 24", allowing 17" of pure foam space.
Super Sized Protein Skimmers

Here is a SK5220 being test run with both input tubes being used. This is being under-driven as part of a test, and is only getting about 400gph per Beckett. Better performance is achieved when the unit is run with the same pump, and a single Beckett.
This is after one week of running.