A protein skimmer is one of the oddest-looking pieces of equipment that you will see in the aquarium hobby with its weird shape, multiple pipes and collection cup filled with sinister-looking dark liquid.
It is, though, one of the most useful pieces of kit you can add to a saltwater tank and a vital part of the filtration system.
We are going to have a look at the best protein skimmers for a saltwater tank but first, let’s have a look at what a protein skimmer is and how they work.
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What Is A Protein Skimmer And How Do They Work
A protein skimmer removes organic proteins from your aquarium water before they have a chance to break down into harmful elements such as ammonia, nitrites, nitrates and phosphates.
Water and air are sucked into the pump at the base of the skimmer. The pump contains a needle wheel impeller which creates thousands of tiny bubbles in the reaction area.
The bubbles then rise up the neck towards the collection cup and as the bubbles rise they bind organic proteins to them. When the bubbles burst, they deposit this waste of organic material into the collection cup.
Once filled, the collection cup can be emptied and then put back in place ready to be filled again.
Top 5 Protein Skimmers
| # | Preview | Product | Quick Review |
| 1 |  | Bubble Magus Protein Skimmers | Best Value |
| 2 |  | Octo Classic Protein Skimmers | Superb Quality |
| 3 |  | Hanchen Protein Skimmers | Decent |
| 4 |  | Marine Color RDC 250 Hang-on Protein Skimmer | Hang-on |
| 5 |  | Hydor Slim-Skim Nano Protein Skimmer | For Nano Tanks |
Why You Should Use A Protein Skimmer
If you are keeping a small nano tank or a fish-only tank you will not necessarily see any great benefits from running a protein skimmer.
Regular water changes should be enough to keep excessive levels of nutrients at bay.
However, for larger coral reef tanks, particularly if you keep SPS corals, a protein skimmer is essential.
A protein skimmer performs two main functions: nutrient export and gas exchange. The improved gas exchange will greatly assist in keeping your PH level stable.
Corals, above all, require stability, and by keeping nutrient and PH levels consistent you are giving them the best chance to grow and thrive.
Another benefit of running a protein skimmer is that, as the nutrient export is so efficient, it can allow you to cut back drastically on water changes.
What to Look for When Buying a Protein Skimmer
There are four main types of protein skimmers:-
In-Tank Skimmers – In-tank skimmers are now only used in nano-tanks and sit inside the display tank.
HOB Skimmers – Hang-on-the-Back skimmers sit on the back of the tank and use a pump to draw water from the aquarium. They should only be used for mid-sized aquariums without a sump.
External Skimmers – External Skimmers sit outside the aquarium altogether and pump water back and forward from the sump. Used only for really large aquariums.
In-Sump Skimmers – In-sump skimmers sit in a dedicated area of the sump and are by far the most popular and flexible.
We look at the best protein skimmers below:-
Protein Skimmer Product Reviews
Here are my reviews of the best Protein Skimmers:-
1. Bubble Magus Protein Skimmers
Bubble Magus produces an excellent range of protein skimmers in sizes to suit all aquariums.
Built to a high quality, the in-sump Curve series utilises a needle-wheel pump for maximum air intake with a cone-shaped body for superior performance.
They run very quietly and can easily be adjusted to produce a dry or wet skim.
Bubble Magnus C3.5 Skimmer
- Capability: 100L-300L (25G-80G)
- Pump: rock sp1000
- Pump power: 8W, 220V 50Hz
- Air intake: 200L/H
- Dimensions: 180 X 120 X 440mm
- Water Level: 8″-10″
Bubble Magus Curve 5 Protein Skimmer
- Capability: 500L (140G)
- Pump: ROCK – SP1000
- Pump Power: 8W, 220V 50Hz /110V 60Hz
- Dimensions :185mm x 180mm x 470mm
- Water Level: 9.5″-11″
Bubble Magus Curve 7 Protein Skimmer
- Capability : 700L-900L(185G -240G)
- Pump: ROCK – SP2000
- Pump Power: 16W, 220V 50Hz /110V 60Hz
- Dimensions: 235×200×530mm
- Water Level :9.5″-11″
Bubble Magus Curve 9 Protein Skimmer
- Capability: 900L–1500L(240G-400G)
- Pump: ROCK – SP4000
- Pump Power: 20W, 220V 50Hz /110V 60Hz
- Dimensions: 235 x 2956 x 600mm
- Water Level: 9.5″-11″
Bubble Magus also produce hang-on protein skimmers for those without a sump or for nano-tanks.
Pros
- Quiet
- Easy to Adjust
- Excellent skim rates
- Easy to clean and maintain
Cons
- Set-up instructions could be clearer
2. Octo Classic Protein Skimmers
Octo classic protein skimmers from Reefoctopus are a range of small-footprint in-sump skimmers designed for aquarium sumps with limited space.
All feature their own Aquatrance pumps specifically made for protein skimmers featuring an “air shredding” needle wheel design.
They run very quietly and are easy to clean and maintain.
The Classic 110-S and Classic 150-S features a straight body with a vented valve output while the Classic 152-S and Classic 202-S features a wine-shaped smooth cone body with a precision control gate valve.
- Classic 110-S – Footprint 200 x 155mm – Tank Volume 500 litres
- Classic 150-S – Footprint 240 x 185mm – Tank Volume 800 litres
- Classic 152-S – Footprint 265 x 205mm – Tank Volume 600 litres
- Classic 202-S – Footprint 315 x 255mm – Tank Volume 1000 litres
Pros
- Superb quality acrylic body
- Small footprint
- Quiet
- Excellent pump
- Superior control valve on the larger models
Cons
- More expensive than Bubble Magus
3. Hanchen Protein Skimmers
Hanchen produces a number of protein skimmers for different tank sizes.
They are decent enough but not the quietest.
- C3 – Footprint 256 x 110mm – Tank Volume 100 – 300 litres
- C3.5 – Footprint 180 x 120mm – Tank Volume 300 litres
- C5 – Footprint 185 x 180mm – Tank Volume 300 – 500 litres
Pros
- Decent quality
Cons
- Large Footprint
- Noisy
4. Marine Color RDC 150 Hang-on Protein Skimmer
If you have limited space why not try a hang-on protein skimmer?
The Marine Color RDC 150 Hang-on Protein Skimmer has a very small footprint of 150 x 90mm.
Best for tanks from 60 – 120 litres.
Excellent build quality with a good pump.
Pros
- Small footprint
- Quiet
- Good pump
Cons
- Smaller tanks only
5. Hydor Slim-Skim Nano Protein Skimmer
The Hydor Slim-Skim Nano Protein Skimmer is for use in tanks below 100 litres.
Water intake is from the surface through a special grid. Includes the Hydor Multi venturi impeller which creates very fine bubbles inside the foaming chamber.
Adjustable air intake valve on top of the collection cup.
Pros
- Magnetic suction cups allow for easy positioning
- Very small footprint
Cons
- Very small collection cup
- Noisy
- Regular cleaning required
Conclusion
The Octo Classic Protein Skimmers are top quality and provide for excellent control on the larger models. They are very efficient skimmers and their small footprint means that they can fit in the tightest of sumps.
That said, we think the Bubble Magus skimmers represent better value for money and will more than do the job. Easy to adjust, clean, and maintain, and with excellent skim rates, Bubble Magus are our best overall pick.
If you are looking for a hang-on protein skimmer then the Marine Color RDC 150 Hang-on Protein Skimmer fits the bill.
As to the Hydor Nano Skimmer, we are not convinced that tanks below 100 litres in volume even require a protein skimmer and there are cheaper ones out there you can try.
Protein Skimmer FAQs
Why do new protein skimmers need a break-in period? – After the manufacture of acrylic, a harmless film of oils is left behind which is resistant to the tiny bubbles and particles produced by skimming. In addition, a bio-film needs to build up inside the skimmer to allow the bubbles to cling to it and rise up the neck.
How long does it take to break in a protein skimmer? – A typical break-in period for a new skimmer will be 1 – 2 weeks but it could be longer depending on the bioload of the tank. Newer tanks will take longer as there will be less waste to skim.
During the break-in period simply allow the skimmer overflow pipe to drain directly back into the sump.
What is wet and dry skimming? – Wet skimming is when the waste in the collection cup is very watery with a pale tea-like colour. This is produced when the water level is set so that the bubbles rise high up the skimmer’s neck.
Dry skimming produces a much darker and thicker waste in the collection cup and arises when the level is set so the bubbles rise lower up the skimmer’s neck.
There is no hard and fast rule as to which is better as it will depend on your tank’s bioload, amount of feeding, number of corals, etc.
Should I run my skimmer 24 – 7? – You should run your skimmer continuously over the full 24-hour period. Only if your tank suffers from very low nutrient levels should you consider reducing the skimming period or turning it off altogether.
Should I turn my skimmer off when feeding? – No, it should not be necessary to turn your skimmer off when feeding. However, certain coral foods have been known to cause a skimmer to overflow so if that happens you can turn off the skimmer for a short period.
Will a protein skimmer help with algae? – Yes, a protein skimmer can help with algae. Algae feed on excess nutrients in your aquarium and as a skimmer reduces those it will help in the battle against algae.
How often should I clean my skimmer? – You should empty your protein skimmer cup as often as required to stop it from overflowing. As to the skimmer body, pump, etc., these should be cleaned as often as you clean other pumps in your aquarium, so around every 4 -6 months.
Do NOT use any kind of detergent though, as this will remove the bio-film that has built up in your skimmer and mean you will need to break it in again.