How does a protein skimmer help keep lobster tank water clean?

A protein skimmer is part of the filtration system in a lobster tank. It uses fine air bubbles to remove dissolved organic waste including proteins and oils from the seawater before they break down and affect water quality. At Todd Fish Tech we fit protein skimmers to our Lobster Pods and Crab Pods to help maintain good water quality when holding live lobsters, crabs and langoustines.

How does a protein skimmer work?

If you’ve ever been on the beach on a windy day you’ll have seen the brown foamy spume that collects where the waves break. A protein skimmer uses much the same process to remove waste from seawater.

Inside the protein skimmer there’s a wooden air diffuser which produces thousands of tiny air bubbles. Organic waste in the water attaches to the surface of these bubbles and is carried upwards as foam through a central column. The foam collects in a chamber at the top of the protein skimmer where it can be removed from the system.

It’s a clever and relatively simple way of removing waste from seawater.

Why is removing organic waste important in a lobster holding system?

Lobsters, crabs and langoustines all produce waste while they’re being held in a recirculating seawater system. Some of this waste comes from the shellfish themselves while some comes from bait and other organic material introduced into the tank.

As organic waste breaks down it can contribute to ammonia production and increase the demand on the biological filtration system. A protein skimmer helps by removing some of this waste before it decomposes. This reduces the organic load on the system and helps maintain cleaner water for the shellfish.

Protein skimmers work alongside the other parts of the filtration system. They don’t replace mechanical or biological filtration but provide an additional way of managing water quality.

Why does a protein skimmer sometimes produce lots of foam and sometimes none at all?

It’s quite normal for a protein skimmer to produce very little foam at times. If there’s not much organic waste in the water there may be very little for it to remove.

When fresh lobsters arrive they can still have bait in their guts. As they produce waste the protein skimmer may become much more active and you’ll see foam collecting in the chamber at the top.

If you suddenly notice an unusually large amount of foam it’s worth checking what’s happening in the tank. There may be an increase in waste production or something else that needs your attention.

How do you empty and clean a protein skimmer?

The waste removed by the protein skimmer collects in the chamber at the top where you can see it through the viewing window. This chamber can be removed and emptied or the waste can be drained through the valve. If there’s a large amount of waste you can also attach a hose to direct it into a suitable container or drain.

Over time the inside of the protein skimmer can become coated in oily or slimy waste. Giving it a clean when carrying out routine maintenance helps keep everything working as it should.

How often should you change the air diffuser in a protein skimmer?

The wooden air diffuser may need replacing around three or four times a year depending on how heavily the system is being used.

Over time the wood becomes dirty and can start to swell. You’ll often notice that fewer bubbles are being produced or that the airflow isn’t as good as it was.

To replace the diffuser you close the air supply valve and disconnect the fitting. Be careful not to lose the little O-ring which seals the connection. The old diffuser can then be unscrewed and replaced with a new one.

Once everything is reconnected and the air is turned back on you should see a good flow of fine bubbles again. It’s also a useful opportunity to clean the inside of the skimmer and the collection chamber.

Our YouTube video above shows you how to change the air diffuser in real time.

Do all Todd Fish Tech lobster and crab holding systems have protein skimmers?

Yes. Our Lobster Pods and Crab Pods include protein skimmers as part of their filtration systems.

We’ve been designing and manufacturing live shellfish holding systems since 1998 and understand how important good water quality is when holding lobsters, crabs and langoustines.

A protein skimmer is just one part of the filtration process but it’s an important one. Working alongside mechanical and biological filtration it helps remove organic waste and supports a healthy holding environment for live shellfish.

You can see how the protein skimmer works and how to change the wooden air diffuser in our video.

 

Last Updated October 2026