Reef Octopus Classic 100-HOB Protein Skimmer Review

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Aquariums get dirty. Fish can produce a great deal of waste, and algae can get out of hand.

The Reef Octopus Classic 100-HOB is a protein skimmer for large aquariums, designed to clean all debris, unhelpful bacteria, and muck out of the water.

reef octopus classic 100-hob protein skimmer

Saltwater tanks, in particular, can become extremely difficult to manage, which is why any experienced aquarist will swear by protein skimmers like this one.

This skimmer is efficient and relatively affordable, though not one for the inexperienced, as no manual, instructions, or warranty accompany the Reef Octopus.

Still interested? Read on for our complete Reef Octopus 100-HOB review!

Reef Octopus Classic 100-HOB Protein Skimmer: The Details


  • Weight: 6 pounds (shipping).
  • Dimensions: 8 x 3.75 x 17 inches.
  • Capacity: 105 gallons.
  • Minimum and Maximum Water Level: 5 inches exactly.
  • Type of Skimmer: External skimmer with a venturi air + water pump system.


Air Silencer

The best protein skimmers all have one thing in common, aside from filtering muck, and that is they run near-silent.

No one wants the peace of their home disrupted by a noisy skimmer. The fact that the Reef Octopus comes with an effective air silencer is a big mark in the pros column.

Collection Cup

Large aquariums mean a large amount of waste needs to be dealt with. So, it is great news that this skimmer is equipped with a large collection cup. This cup, too, is easy to remove and clean.

This cup does have issues, however, with overflow occasionally spilling out of the chamber and onto users’ nice, clean floors.

Aquatrance Pump

In order to keep the overall design simple, an Aquatrance pump has been used to power the Reef Octopus.

This filter creates an optimal mix of air and water, pushing both through the various chambers and back into the tank.

This means that no air-stone is needed and that the water entering back into the aquarium is oxygenated to the max. This is great for those without live plants but who have tanks with a high population!

The pump sits inside the aquarium, and can be a bit of an eyesore, but with the clever placement of decorations or plants, you won’t even know it’s there.

External Skimmer

Though capable of handling aquariums up to 105 gallons, smaller tanks will benefit from a protein skimmer as powerful as this too – not only because of how well it works, but due to it being an external skimmer that hangs over the back of the tank.

Taking up minimal space in the tank means that there is more space for fish, plant-life, coral, and decorations!

reef octopus classic 100-hob review


It’s probably the most upsetting when you’ve invested in a pump or skimmer for your filter and gain no results. You won’t have to worry about that issue with the Reef Octopus 100-HOB skimmer.

This skimmer is made to be powerful, working in overdrive to keep your tanks and aquariums crystal clear and free of gunk.

This way your fish can steal the spotlight without ugly distractions.

Some users do mention a short ‘break-in’ period where they played with the adjustments and set-up until they achieved the best results, while other users noticed a big difference straight away.


Aside from the Aquatrance pump, high-quality acrylic has been used to build the body of the skimmer.

Acrylic is scratch resistant, offers a degree of clarity and security that other clear materials cannot, and is easy to clean.

Easy Installation

As skimmers of this style typically are, installing the Reef Octopus is incredibly easy – all one has to do is hang the skimmer over the back wall of the aquarium, plug in the filter, and flick the power on. Easy!

Reef Octopus Classic 100-HOB Protein Skimmer Review

The Positives

Good for Waste-Heavy Tanks

The Reef Octopus is a skimmer capable of getting the job done, and done well.

Most of us have dealt with filters that clog up too fast, or seem to remove only the largest pieces of waste, leaving the tank in an unpleasant state.

We want our aquariums in peak condition. This skimmer is a step in the right direction.

Ease of Use 

With the Reef Octopus Classic skimmer, you can let it do all the work thanks to how easy it is to use.

Assembly and set-up should take you little to no time at all, and once it’s up and running it’s a walk in the park.

This also makes the daunting task of cleaning your skimmer all the easier. When a skimmer is easy to assemble, you can count on it being just as straightforward to take apart so you can clean it out.

And when you’re ready to make adjustments to it, it won’t leave you fumbling and frustrated.

Whether you’re a beginning aquarist or have been doing this for years, the Reef Octopus won’t take a lot of getting used to thanks to its small learning curve.


At under $200 this is an affordable skimmer. Saltwater aquariums are not cheap to start up or maintain, and the fact that the Reef Octopus is a skimmer that can work with budgets is a great feature.

That doesn’t mean it lacks on quality either though, its built with high-quality acrylic and durable pieces to give you a great bargain.

High-quality acrylic is typically used to make top of the line aquariums due to its structural integrity and clarity.

The fact that a material of this grade has been used to construct the Reef Octopus is a huge bonus, and promises a long lifespan and easy cleaning – no matter how much skimmate the skimmer removes from the tank.

best protein skimmer

Space Saver

The Reef Octopus hangs over the back of your aquarium, out of the way and safety tucked where fish can’t accidentally become stuck.

The Aquatrance pump, too, is easy on tight spaces. Small, though certainly not underpowered, this pump can be kept out of sight.

Because of this, the Reef Octopus is a great skimmer for those with high-population tanks, as it can deal with the waste, keep the fish healthy, and won’t eat up too much room.


We’ve all had an aquarium so noisy that it drove us up the wall. Eventually, we get so fed up that we either replace the noisy equipment or shove the aquarium into another room.

Luckily, noise will not be an issue with the Reef Octopus. The motor is quiet despite how powerful it is, and it won’t bother even those with sensitive hearing.

No Overflow (Most of the Time)

Aquariums come with their fair share of problems, such as overflow. It really, really sucks to come home and find half of the tank’s water on your living room floor.

Reef Octopus knows this, and has designed the skimmer to manage overflow; should the water level or skimmate rise, overflow typically drains back into the tank. Whew!

The Negatives


Despite the large collection cup and how overflow should drain back into the aquarium, there have been reported issues with the whole system overflowing and spilling onto the floor.

Considering how many litres per hour this skimmer can churn through, this is not a small amount of water potentially ruining your carpet either.

Daily Maintenance 

While most of us won’t complain about a crystal clear tank, we will note that the Reef Octopus is so powerful that some users have reported having to empty the collection cup at least once a day.

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This is a clear indicator that the protein skimmer is performing at its best, but those on a busy schedule or those who just lack the time to clean every day might find that this daily task can be inconvenient.

Fortunately, cleaning is easy so while adding this extra task to your list won’t throw you off too much, it’s still another thing to tend to.

Keep in mind that this isn’t always the case, as some other customers recorded only having to empty their collection cup once every week.

No Manual or Instructions

This is a large part of why this skimmer is not for the inexperienced – or those that despise puzzles.

No manuals or instructions come with the skimmer, nor does Reef Octopus indicate that they have a how-to guide up on YouTube.

Aside from being incredibly frustrating, this shows a lack of consideration on the part of the manufacturer. There have been reports of rather unhelpful customer service too.

There’s little mention of any warranty or customer guarantee which is important when purchasing a product such as this online. You’ll have to contact the company or retailer for more information.

If you aren’t up for the challenge of putting this skimmer together, or aren’t okay with a bit of uncertainty then look elsewhere.


This is a large skimmer. Given the volume of skimmate and water the Reef Octopus has to deal with, a bulky skimmer isn’t a surprise.

Still, it is worth pointing out that you will need a fairly large gap behind the tank for it to fit.

No Drain Line

Ah, overflow. We have brought it up a few times in this review.

The reason why overflow often occurs in skimmers is due to a lack of drain line, which would deal with excess skimmate and water.

Reef Octopus has no drain line, and thus the issues with overflow.

Here’s a video showing what the Reef Octopus Classic Protein Skimmer looks like out of the box.

Overall Verdict

The Reef Octopus Classic 100-HOB Protein Skimmer is a beefy machine that will remove even the smallest particles of skimmate from your saltwater aquarium.

An external filter armed with an Aquatrance pump makes for a powerful duo, and despite the odd overflow issue, this skimmer is definitely one to consider.

If you have a high population tank that needs throughout cleaning, then the Reef Octopus is the right fit.

Where to Buy the Reef Octopus Classic 100-HOB Protein Skimmer

The Reef Octopus Classic Protein Skimmer has been turning many heads with this affordable solution to a clean and quiet tank.

This skimmer is rising in popularity featured in a number of aquatic shops both in-store and online.

To start your search, check out the following online retailers.

And of course, you can also find this skimmer on Amazon.

reef octopus classic 100-hob protein skimmer

That’s a wrap on our review of the Reef Octopus Classic 100-HOB Protein Skimmer. Tempted to give it a go?

Reef Octopus Classic 100-Hob Protein Skimmer Rated
  • Efficiency
  • Build Quality
  • Ease of Use
  • Noise Levels
  • Value for Money

FCG Verdict

The Reef Octopus Classic 100-HOB Protein Skimmer is an affordable solution to a crystal clear tank.

Don’t let the price-tag fool you, this skimmer is powerful, easy-to-use, and quiet, made with high-quality materials so you know it won’t flake out.

>>> Check current price on Amazon.

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