The Ultimate Guide to Protein Skimmers
September 09, 2017
Written by Dan
When you first get into saltwater aquariums a term that is sure to come up very early when deciding what equipment you need is “Protein Skimmer.” If you are like me and just about every other aquarium owner I have talked to there are going to be a hand full of questions you will likely have. In this article I aim to answer those questions so you can have a happy and healthy tank.
Here is exactly what we are going to cover
- What does a Protein Skimmer do?
- Do I have to have a Protein Skimmer?
- Quick recommendations by Tank Size
- How does a Protein Skimmer work?
- Styles of Protein Skimmers
- Hang On the Back
- Single Pump
- What maintenance is required with a protein skimmer?
- Does size and shape of the protein skimmer matter?
- What size Protein Skimmer should I use?
- Review of best protein skimmers by tank size
What does a Protein Skimmer do?
In plain terms, a protein skimmer removes unwanted organic compounds including protein and amino acids from your aquarium water before they can aid in feeding unwanted algae. These compounds are microscopic and diluted into the water. They are typically so small that nets, socks, sponges, cloth, etc. cannot catch them. If not removed, these particles will decompose adding to the Nitrogen cycle. The protein skimmer removes them before they have a chance to decompose.
Do I have to have a Protein Skimmer?
Ultimately no, but it is highly recommended. A protein skimmer removes many unwanted items from the water that could be removed with regular, often larger, water changes. The increased water changes impact both the time you need to spend maintaining your tank as well as the cost to maintain it. It is commonly recommended to do weekly water changes of 10-15% of your systems total water capacity, and that is with a skimmer. Without a skimmer I would recommend increasing that to 25-30% each week. If you have a smaller tank, say a 20 gallon, doing a 25% change is only 5 gallons and would cost just a few dollars. A 60 gallon, 90 gallon, or in my case 180 gallon tank becomes much more time consuming and costly to do that. If I changed 25% of my tank each week that is 200 gallons per month!!!
For your convenience we have provided the break out below that shows our top picks for several common system sizes. Size ranges are based on total system size not just what size your tank is.
The SLIM SKIM by HYDOR is my top choice for this size tank. They have both a full size for up to 55 gallon and a NANO for up to 35. It is sleek hides in the corner of the tank and looks like a overflow box. If you have a tank that has a filter compartment these even fit inside many of those.
I choose the Reef Octopus Classic 150 Space Saver Protein Skimmer for this size setup. The Aquatrance 1800s Pinwheel Pump in this sleek and slim skimmer pushes up to 140 GPH. The pump sits in the bottom of the skim chamber reducing the area needed in your sump freeing up valuable space while still being a beast of a skimmer.
I use the Reef Octopus Classic 202-S Protein Skimmer in my 180 Gallon Reef tank at home. This tank sits right in my living room and is a focal point for guests when they first walk through the front door. From day one this skimmer has worked like a champ. I often get comments from people that they can’t believe how clear the water in my tank is, and I know that is because of this baby.
How does a Protein Skimmer work?
Protein Skimmers remove unwanted compounds from the water by feeding water and lots of little air bubbles into a compact usually roundish (yes roundish is a technical term) compartment where the bubbles can rise above the water. As the bubbles raise they lift the unwanted particles out of the water at which point they can be skimmed off the top of the bubbles. Typically a protein skimmer will have collection cup at the top for all of the crusty bubbles to overflow into. Once in the collection cup they are out of your aquarium and will no longer feed the nitrogen cycle.
The more in-depth explanation talks about how the electrical charge of the nasty particles will either stick to or repel against that of the many bubbles in the skimmer. Since the bubbles rise up through the skimmer the electrical attraction of the crud to the bubbles will push and pull the crud to the top with the bubbles. Since the skimmer has many, many, many small bubbles there is a lot of surface area to move the gunk along.
Styles of Protein Skimmer
There are three main styles of protein skimmers to consider in today’s market. Those are the single pump including space savers skimmers, recirculating skimmers, and hang on the back skimmers.
Hang on the back skimmers are intended for filtration systems that do not have a sump. They are usually rated for smaller sized tank and are generally only recommended when you have an un-drilled tank. I personally have run these successfully myself on some of my older tanks and they make a great choice for someone who has a fresh water tank and are looking to convert it into salt water. Ultimately hang on skimmers are small versions of the single pump design setup in a manor so they can be hung on the back or side of the aquarium. There are many models on the market now that are classified as Hang on skimmers but they sit in the tank either still clipped to the lip of the aquarium or attached to the glass with magnets like a powerhead. This style eliminates many concerns people have had over time with overflows of the collection cup into your floor.
Single Pump Protein Skimmers are probably the most common style of skimmers on the market today. Back when I bought my first protein skimmer some (I’m not telling) years ago, skimmers were simply a very strong air pump with a wooden block at the end of it shoved into a plastic cylinder with at cup at the top. The movement of the bubbles up would pull water through the tube to get new water in the bottom to clean. Single Pump Skimmers are water cleaning beasts in comparison to those old models.
A single pump skimmer will use a specially designed pump to both move water through the skimming chamber and to suck air into that water stream. While in the pump the air and water are whipped together using a needle-wheel which creates a very foamy looking micro bubble. This process can create thousands of bubbles which have tons of surface area for the size of the chamber they are pushed through.
Single pump models are found with the pump mounted outside of the bubble chamber and in space saving models that place the pump inside the bubble chamber.
The downside to the single pump design is that since the pump is handling both the water flow and air flow of the skimmer it is highly impacted by the water level in your sump. Depending on the setup of your sump and if it has any sort of baffle design you may have to prop up the skimmer using plastic egg crate, bio blocks, or another tank safe material. Also if you don’t have an auto top off system the fluctuation of the water level could impact efficiency between top offs.
All of these downsides can easily be overcome with just a little thought and planning. Adding a baffle or two to keep water at an exact height in the section of the sump where your skimmer sits or an auto top off can easily eliminate all of these concerns.
Recirculating Protein Skimmers take the design of the single pump skimmer to the next level. Plumbed in a manor that moves the water through the skim chamber more than once along with separate intake for both air and water. This style of skimmer gives you individual control over air injection and water flow. Having this level of control allows you to control how long water remains in the skimming chamber and thus how clean it gets before leaving.
Since the water flow is handled by a separate water feed pump the water level of your sump is not a factor as with single pump designs. This is also the style of skimmer you would want if you wanted your skimmer sitting outside of the sump altogether.
What maintenance is required with a protein skimmer?
There is not a whole lot of required maintenance to keep a skimmer working if everything is setup properly. The main thing is just to clean out the collection cup as needed. I personally clean mine out about every 2-3 days. Depending on what is in your tank and how much you feed it you may need to do this more or less often. I will say though that the stuff this pulls out of the water has a wonderful aroma after it sits for a bit and for that purpose alone I wouldn’t want to let it sit more than a few days.
You should also clean the pump and pin wheel about once every six months to remove any calcium buildup or other gunk that could reduce its effectiveness and over time prevent it from working altogether. Using a small scrub brush and an acid dip formulated for this purpose like Tunze Citric Acid.
Does the size and shape of the protein skimmer matter?
I hate this answer but yes and no. If you ask a hand full of aquarists or read through a few forum threads you will get a variety of answers that are all correct. The reason for that is because every system is different with different critters, lighting, feeding habits, and cleaning habits.
As for shape they vary from standard cylinders to cones and even wine glass shaped bodies. Each style has its own lovers and haters but I have never seen any hard evidence to prove one shape improves bubble movement over another. The only argument I have seen in any one direction is that a cylinder would have more area inside it when compared to a cone or wine glass design of the same height and base circumference. This could assist with increased dwell time, or rather how long the water sits in the chamber being cleaned.
Contrary to anything you have been told, size matters. The bigger the skim chamber, the more water and bubbles it can hold, the cleaner the water. But a big chamber with a little pump can’t move the ocean either. So a massive skimmer can still be out performed by a well-tuned smaller model. Alrighty then, let’s get our minds out of the overflow cup and move on.
What size protein skimmer should I use?
Always use the total amount of water your system holds not the size of your tank when determining what size skimmer to get. For example, my 180g tank has a sump that holds about 40g when the pumps are off and all the pipes have drained down into the sump, so I would need a skimmer that can handle 220g.
Also, I say get the biggest one you can afford, but remember what I said in the last section about having a good reliable pump to match the size of the skim chamber. Don’t worry about over skimming; even though protein skimmers also remove small amounts of trace elements like iodine and even some phytoplankton that could feed your coral these can easily be replaced by using additives and spot feeding the coral I wouldn’t really worry about over skimming. To be honest those are things you should be doing even with a smaller skimmer. The pros outweigh the cons so get the biggest best skimmer 1. You can comfortably afford and 2. Fits in your system.
The truth is we all like to add more in our tanks and we like to feed more than we should. This is why having the larger skimmer makes a difference. If you have a 60 gallon and can afford the skimmer rated at 90 gallons and it fits in your sump, go for it. On my 180 I run a Reef Octopus Classic 202 which is rated at 265 gallons.
Now that we know all about why we should have a skimmer and the different types of skimmers out there, let’s take a closer look at a few specific models and see if we can’t help you select the perfect skimmer for you tank. All of our recommendations are based on our own experience with these models, the track record of well known and trusted companies in the industry, as well as the experiences and testimonies of other.
Protein Skimmer Reviews for 2019
Small to Medium tanks with no sump
55 Gallon and under
The NS80 is rated at 10-25 gallons depending on bio load. It hangs on the back using clips that sit over the edge of the tank with the main body of the skimmer sitting within the tank. It uses one of the smallest pin wheel pumps on the market giving it great performance for its size. This is a great option for someone with a Nano cube that has a small separated compartment across the back of the tank. Although it not a bad looking skimmer some people may not want to see it from the front view of the tank. At this price point though it would also make an excellent skimmer to throw in a 20 gallon frag grow out tank.
Hydor is known for making a solid product that rest somewhere in the mid-range price point. They didn’t let us down with the SlimSkim. The regular version is rated for 48-65 gallons and the nano is able to handle 25-35. The square shape of the outer body hides the internal cylindrical skim chamber and it reminds me of an overflow box and could be placed in a corner or the center of the back wall of the tank giving the impression of a drilled tank. The mounting mechanism uses two magnets on the outside of the glass to hold it in place and if you want to slide this into the back partition of a nano tank the mounting brackets are removable. This is the skimmer I wish was around the first time I decided to turn one of my 55 gallons into a Saltwater tank.
Medium to Large Tanks with a Sump
60 to 120 gallons
Reef Octopus has been around since 2005 and is a very trusted name in the industry. The 110 space saver is rated up to 120 gallons, it is designed to sit inside your sump, and has a very small foot print of only 6.1” x 7.87”. These facts mean this is a perfect skimmer for anything from a 60 to 90 gallon tank with an appropriately sized sump.
This 6” Recirculating Skimmer Is one of the few recirculating skimmers I recommend. That is not because they are not effective, on the contrary they are the best style on the market if you have the money and the space. That is just the problem many hobbyists are short on available equipment space, money, or both. Recirculating skimmers take up more of both and I have tried to stick with good cost conscious and space friendly models. If you have somewhere around a 120 gallon tank and 20-40gallons worth of sump this is a great skimmer. It gives you the option to plumb it external or to simply sit it right in your sump. Giving control over both water and air flow separately you have great control over dwell time. Its footprint is 12.2”x10.4” since the pump sits outside the 6” skim tube and is 25.6” high. If I were to setup a 120 gallon tank this would be the skimmer I went with.
The Skimz Monzter is another space saving model that houses the pump inside the skim chamber to allow for more adaptability inside your sump. This skimmer is rated by the manufacturer for 132 – 317 but is recommended for 120-180 gallons based on most aquarist’s tendencies to overstock a tank, I know I do. The bubble plate design helps with bubble flow in the chamber and the easy screw control air inlet helps you to adjust how much air is pulled in giving added control over bubble flow.
Larger Tanks with a Sump
160 to 220 gallons
This is actually the skimmer I am running right now on my 180. As I said earlier I have a 180 tank with about 40 additional gallons in sump and pipes. The 202 is rated to handle 265 gallons. This means that for even a monster 220 gallon tank with a 40 gallon sump underneath this sump has you covered. My tanks like many other hobbyists came together in pieces meaning I bought a few items here and there over several months. I had just been running filter socks for the first three months when I setup the tank this is on now, and wow! For the next week I was cleaning the cup daily and watching some of the nastiest crud collect in it. My water went from nice looking like I had filled it with bottles of FIJI water out of a bottle. The turn knob allows for easy adjustments of water flow so you can fine tune the bubble height in the chamber. If you have a big boy tank and want a good skimmer I would highly recommend this to anyone.