Reef Octopus

Reef Octopus Classic 90 Hang-on-Back Protein Skimmer

In stock
Out of stock

- +

Unique skimmer design with cylindrical body which uses the siphon to feed water to the skimmer. This reduces the load on the pump while increasing the air intake.

  • Rated for aquariums up to 100 gallons
  • Powered by Aquatrance 1000 Pinwheel Pump
  • Design reduces turbulence
  • Capable of surface skimming
  • Collection cup is easy to remove to empty


Well Stocked Tank - Rated up to 75 gallons

Medium Stocked Tank - Rated up to 90 gallons

Light Stocked Tank - Rated up to 100 gallons


Skimmer Features:

  • Traditional body design
  • Air silencer
  • Pump mounted externally on skimmer
  • Easily remove collection cup for cleaning
  • Solid construction
  • Control - precision output valve
  • Removable turbulence reducing bubble plate


Skimmer Specifications

  • Body Size: 4"
  • Footprint: 7.5" x 7.5"
  • Total Height: 23.8"


Aquatrance 1000s Pinwheel Pump Features:

  • Power Consumption: 9 Watts
  • Air Draw: 454 lph*
  • Water Draw: 350 lph/92 GPH*

*Aquarium set up will determine air and water results.



  • 2 year warranty on pump
  • 1 year on skimmer body


pdf iconReef Octopus Classic 90 HOB Protein Skimmer Manual

Item #: OCT-BH90

More Information
UPC 6950291205384
Skimmer Type External, Hang On Back
Capacity Light Bioload - up to 100 gallons
Medium Bioload - up to 90 gallons
Heavy Bioload - up to 75 gallons
Dimensions 7.5"L x 7.5"W x 23.8"H
Diameter 4"
Max Tank Thickness 2 in.
Output Size 1.25" (1-1/4 in.)
Air Draw 454 LPH
Flow Rate 92 GPH
Pump Model Aquatrance 1000S
Pump Rotor Type Pinwheel
Variable Speed No
Power Type AC
Power Consumption 9 Watts
Warranty 1 Year (skimmer body), 2 Years (pump)
Pump Included Yes
Write Your Own Review
You're reviewing:Reef Octopus Classic 90 Hang-on-Back Protein Skimmer
Your Rating
Only registered users can write reviews. Please or

Product Questions

Will this mount onto a 75g Aqueon tank? The tank has the standard black frame brace and it is approximately 1 1/8 wide.
Question by: Terry Carrico on Jan 18, 2023, 8:24 AM
Hey Terry, thanks for the question! It will work on rimmed tanks!
Answer by: James Johnson (BRS Staff) on Feb 8, 2023, 5:36 PM
I have a couple of skimmers of this make and model. Can a "Universal CO2 Scrubber - Bulk Reef Supply" be connected to this make and model skimmer?
Question by: Sherwood Shivar on Jul 18, 2022, 8:49 AM
Thanks for the question! This can be done, however, is a bit more difficult than other models as you'll need to remove the air silencer and measure the tubing. You may need an adapter to get from the 3/8" tubing of the scrubber to the tubing on the skimmer. Let us know if we can help with anything else!
Answer by: Kyle Thomas (BRS Staff) on Jul 19, 2022, 12:52 PM
Will this fit on a 32 biocube. I'm looking for a hob skimmer?
Question by: Alex on Dec 28, 2018, 12:28 PM
Thank you for reaching out to Bulk Reef Supply! Unfortunately I would not recommend this skimmer for the BioCube line. The BioCubes are an enclosed design leaving no exposed surface are when the lid is shut. The Reef Octopus Classic 90 HOB would need access to the surface of the water and unless you are planning a DIY job this skimmer would not work for this particular tank. I hope this was helpful. Please reach back out if you have any further questions!
Answer by: Ashley on Jan 7, 2019, 4:35 PM
How much clearance do I need between the back of tank and a wall?
Question by: Larry D. on May 14, 2017, 7:40 PM
Hey there,
You'll want about 6" of clearance behind your tank to be able to maneuver this skimmer in and out.

Have a great day!
Answer by: Zack on May 17, 2017, 3:16 PM
Is it ozone compatible?
Question by: Paul D. on Jun 28, 2016, 9:00 PM
Reef Octopus Skimmers are made of 100% ozone safe material.
Answer by: Connor on Jun 29, 2016, 6:56 PM
Is it possible to hang this off the side of my sump and still get the needed water level for this skimmer? My water level is 7 inches. I'd get an in sump protien skimmer but my sump is just a tad bit small, its 5 3/4 inches wide :(
Question by: Coulter on Jun 4, 2016, 5:27 PM
Great question!
This will need the water level to be around 2-3 inches below the rim for the siphon to start. As long as the water int eh sump is high enough to keep the intake and output submerged. Feel free to let us know if you have any further questions!
Answer by: Connor on Jun 9, 2016, 2:10 PM
What is the distance that this hangs off the side of the tank? i've got a 20 long, that's roughly 13" tall that sits on my dresser, and i'd like to know if this will sit on top of the dresser, or would I need to move the tank to a side so it'll hang off?
Question by: Mitch on Apr 7, 2016, 6:59 PM
Great question!
This will hang 12.6" down from the top rim of the tank. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 7, 2016, 10:02 PM
The output tubing from the collection cup uses what size tube? I need to purchase one that's longer than what was supplied. I'm thinking like 1/4 inch but I wanted to double check and was wondering if you sell it?
Question by: Jakob on Apr 6, 2016, 9:03 PM
Great question!
This will use metric tubing however most likely you will want to measure the barb that attaches and find soft tubing in either 1/4" inside diameter or possibly you may need 3/8". Ideally you will want to check first on the unit and see if your local hardware store has soft tubing measured by inside diameter. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 13, 2016, 3:58 PM
Hi, a little new here to saltwater community. I have 36 gal FOWLR tank. Current skimmer from lps has stopped working. Looking at this one. Does it require a sock or pellets or anything that goes inside other than what's included in manufactoring? Can I just set it in and plug it up? Thanks
Question by: Karissa on Apr 5, 2016, 6:57 PM
You will not want to place any media or items in the bubble reaction chamber as this will be where the bubbles are formed. It can simply be mounted on your tank and be set up right away. Feel free to let us know if you have any further questions!
Answer by: Connor on Apr 12, 2016, 4:12 PM
Can this pump be put in a sump? The motor submersed in water
Question by: Ryan on Mar 2, 2014, 1:24 PM
Hi Ryan,
If you have a sump you wouldn't want one of the HOB back versions, just the regular in sump versions. The HOB systems are designed for sump-less systems and require the water level to be near the rim of the tank its sitting on, because sumps have much lower water levels a HOB skimmer would end up out of water in a typical sump.
Answer by: Bulk Reef Supply on Mar 2, 2014, 1:24 PM