Reef Octopus Classic 100 Hang-on-Back Protein Skimmer

Reef Octopus Classic 100 Hang-on-the-Back Protein Skimmer
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  • Reef Octopus Classic 100 Hang-on-the-Back Protein Skimmer
  • Reef Octopus Classic 100 Hang-on-the-Back Protein Skimmer Pump
  • Reef Octopus Classic 100 Hang-on-the-Back Protein Skimmer Silencer
  • Reef Octopus Classic 100 Hang-on-the-Back Protein Skimmer Chamber
  • Reef Octopus Classic 100 Hang-on-the-Back Protein Skimmer Lower

Reef Octopus Classic 100 Hang-on-Back Protein Skimmer

94% Recommend this to a friend (30 of 32)

SKU: 204056

reg. $174.99

Special Price: $157.49

In Stock: 35
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What's This?

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Quick Overview

  • Manufacturer rated for tanks up to 75 gallons

  • BRS recommended for tanks up to 50 gallons

Easy to use, hang-on-the-back skimmer. Hang the skimmer on the back of the aquarium, mount the pump in place per instructions and it is ready to skim. Powered by the 1 Aquatrance 1000 pump with high performance venturi injection system and pinwheel impeller. Built with high quality acrylic.


Full Details

Owners Manual

  • Pump is mounted internally and skimmer rests outside the tank
  • Uses metric plumbing parts
  • Dimensions: 8" x 3.25" x 17"
  • Manufacturer rates skimmer for tanks up to 75 gallons
  • BRS recommended for tanks up to 50 gallons
  • Powered by 1 Aquatrance 1000 pump
  • Maximum air draw: 111 GPH
  • High performance venturi air injection system
  • 1 year warranty on skimmer body and pump


Items 1 to 12 of 32 total

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  • Help By Sue on 11/7/2017

    I keep seeing people talking about break in time. How did you do it without water all over the floor? My cup fills up in minutes! Not sure if I could recommend it or not at this point. And the directions are pretty useless.
  • Awesome BUY By Chris on 1/3/2017

    After five or so years, many diy and store bought purchases (from tanks to Skimmers and sumps to Refugiums, this has been my best improvement yet. I started with a small Tunze 9004 in a 20 gallon Long and kept it when i moved to a 38 gallon and a ten gallon sump (scrapped the Fuge).
    Getting ready to buy a cuboid shaped frameless/rimless and build a stand to house my sump and ATO tank. This is one of the few improvements/changes before the tank comes. VERY PLEASED!!
    Easy to set up, allow for break in and see how the foam builds! Incredible performance, VERY quiet even compared to a tunze 9004. Much more powerful pump and a good sized collection cup. Should last a long time!
  • Good By Darryl on 7/21/2016

    Bought this for my 30 reef as a temporary skimmer, It works very nice, think I will keep it!
    You must keep the cup above the overflow hole and correctly prime it for first run and then it runs by itself.
  • Great Skimmer By Cody on 3/6/2015

    Pros: Works awesome, very quiet

    Cons: Kind of bulky for a hang on the back model, slight eye sore in the tank

    Notes: Possibly a common error, but when starting this skimmer for the firs time, leave the cache can off, i had mine adjusted to the very bottom and water kept spilling over onto the floor. Place the cache can slowly moving it down further until you have no over flow. Overall, great product!!!
  • Awesome Quiet Skimmer By Mike on 12/26/2014

    Got this skimmer for Christmas! As soon as I turned it on it went crazy because I just upgraded and decided I really need a skimmer. Went from a 10 G to a 20L and have this on my 20L, it pulled decent yellowish/greenish skimmate as soon as I turned it on. Compared to the 10, the fish tank is lightly stocked (pair of clowns, six line wrasse, cleaner shrimp) and basically did a 50% water change when adding this skimmer. It is very quiet and still in the break in period so I hope the skimmate gets dark as said. I gave it 5 stars because it was easily assembled although the directions weren't that helpful but its well built and QUIET.
  • Reef Octopus BH100 By Guy on 5/22/2014

    Works great. Just let it break-in and fine tune it. Easy, easy, easy. Performs great and super quiet.
  • Great Skimmer By Lionel on 4/10/2014

    I'll save you hours of research. This is a well built, relatively quiet skimmer. I was looking for a skimmer for my 50 gal breeder and I'm very happy with Reef Octopus's products. My only regret is not going with the 1000 or 2000, mostly because of the external mounted pump and 50 gallons seems to be the biggest tank I would put this on.
    Overall, a great product that does what it says.
  • Awesome Skimmer! By Adam on 3/28/2014

    A great skimmer for someone who is still new to the hobby. I've only been keeping saltwater tanks for a little over a year and this is one of my best purchases, next to an RO/DI system. It took a little over 48 hours for it to break in and start producing a light skimmate. After a week I had some nice, dark skimmate being pulled from my tank.

    The only negatives to this skimmer are the directions and the in tank pump. Youtube quickly solved the directions problem and the in tank pump does take up some room in my 29gal tank, but the way the pump is set up it skims the top of my water which I really like! The only other downfall is the open side of the skimmer leading to the return. This just adds a little more to the salt creep and evaporation - but that's what top off RO/DI water is always for.

    Even with the few downfalls I still give this skimmer a 5/5 because of the quality build of the skimmer and how it functions so quietly. My old Coralife super skimmer was extremely loud and this skimmer is the complete opposite.
  • My first real skimmer By N. Clark on 3/7/2014

    After spending quite a few months researching skimmers for my new 45gal tank it came down to two models; the Reef Octopus and the Aquamaxx. After talking to some people on a few reefer forums, seeing a huge one up close at my local zoo, and chatting with a few LFS employees I ended up with this one. It was pretty easy to put together even though the instructions are a little useless.

    Once I got her up and running she started pulling things out of the water right away. I was having to empty the cup two-three times a day for the first few days. Now that its been about a week or so it's down to every other day or so.

    It's a very quiet skimmer. Just a little bit of noise when it first starts up. I think my Marineland filter makes a racket compaired to it.

    All in all though I am very happy with it!
  • Excellent By Keyser Soze on 3/7/2014

    I'm very pleased with this skimmer. It's well built, works well, and is quiet as a mouse. It comes mostly put together, just look at the diagram to complete the assembly. There is no priming of the pump, no bubbles in the tank, or any surprises involved. Just plug and play.

    The only negative is the supposed "surface skimmer" intake is too short to reach the surface (for me). I think there have been several versions of this skimmer and they add small improvements with each version.
  • Works as stated By Eric on 1/1/2014

    The directions suck, the skimmer works great , if I were to do it again I would get the BH1000 model instead because it has the pump outside of the tank. I knew this when I got it but was in a hurry. My water is crystal clear in a 40 gallon breeder tank with a Greenspotted pufferfish.
  • Good Quality - Quiet Operation By Mark on 12/29/2013

    Good Skimmer for a good price.
    Quality Construction
    Bad Directions.


Ask a question

Product Questions

Can this be used with a 10 gallon sump that is located on the floor? I keep 10 inches of water in it, but I'm wondering if the powerhead would be fully submerged or not? Otherwise what else would you recommend?
Question by: Tom on Jan 7, 2017 2:35:00 PM
Great question! You will need a tank that is at least 13" tall to properly "hang" this skimmer on a tank that is resting on the floor. :-)
Answer by: Randy (Admin) on Jan 11, 2017 11:59:00 AM
Hello i just oreded mine and im super excited im just alittle worried about the overflow ive been doing some research and i cant find anything on sertting it up so it wont over flow to my carpet do u guys have any videos on how to start it ?
Question by: Edmond on Mar 26, 2016 12:12:00 PM
Great question!
Overflow with hang on back skimmer is an inherent risk and will need to be set up under observation for the first several hours and possibly even weeks during break in. You essentially will move the o-ring on the collection cup to set the cup at its highest level. Once a day for the first week you can slowly lower the cup until the skimate is forming. Feel free to let us know if you have any further questions!
Answer by: Connor (Admin) on Mar 28, 2016 11:58:00 AM
Will this mount properly on a rimmed aqueon aqaurium?
Question by: Shelby on Dec 12, 2016 3:14:00 PM
Great question! This will work well with rimmed as well as rimless tanks! :-)
Answer by: Randy (Admin) on Dec 13, 2016 2:25:00 PM
How much clearance would I need behind my tank?
Also I have a 75 gallon lightly stocked only two medium size fish. Would this skimmer be a good choice?
Question by: Adam on Nov 22, 2016 3:07:00 PM
Great question! You will have to account for 3" of clearance behind the tank for this skimmer. It is BRS recommended for 50gal tanks, so you may be better served getting the BH1000 instead. :-)
Answer by: Randy (Admin) on Nov 22, 2016 5:18:00 PM