It is important that you know how to get rid of protein foam in an aquarium. These foam bubbles are not what you would want to see in your beautiful aquarium and they can actually harm your fish.
Your aquarium was running perfectly and one day you saw those strange foams on the surface, which left you worried, rightfully so.
Not to worry. In this article, I will talk about what those foams are and why they appear. I will go into why you should be concerned about them and then we will discuss how to remove protein foam in an aquarium. Let’s get started!
Protein Foam in an Aquarium: What is it
Your aquarium is a tiny ecosystem with various living creatures (not just the fish), so it is no surprise that it gets dirty over time. Your aquarium will collect organic waste in the form of fish food, fish poop, and even dead fish and plants.
Among other things, this organic waste will create a biofilm that will find its way to the surface. This protein film tends to trap air and turn into foam, which floats on the surface.
You would be seeing this protein foam more often if you have a saltwater aquarium, while freshwater aquarium owners may also have to deal with this issue.
Other Things That May Cause Foam
Before we jump into how to get rid of protein foam in an aquarium, it is prudent to know whether it actually is protein foam – there are many other substances that can create foam in your tank.
Agitated Water – You can cause foam simply by agitating the water. When you cause disturbance on the surface, you will invariably cause bubbles to be formed. Try it out in a water bucket or bathtub and see what I mean. This usually happens if you have recently poured water into the tank carelessly. This kind of foam will dissipate on its own and is not a problem.
Soap – You probably know this: soap can cause bubbles. If you see foam with a rainbow shimmer, it is probably caused by soap. If that’s the case, you should remove your fish from the tank IMMEDIATELY – soap is harmful to fish, even in small amounts, and can kill them. Only introduce your fish back into the tank after you have removed the soap completely.
Fish Saliva – Sometimes, your fish is the culprit. Male Labyrinth fish such as Betta, Gourami, and Paradise create a ‘bubble nest’ by blowing through their saliva. They do this to attract any females around. This foam is pretty harmless and you would not want to destroy all their hard work, so don’t pop their bubbles (forgive the pun).
Why is Protein Foam Bad for Your Aquarium
Now, the most pressing question you may have is probably this: can protein foam kill fish? Well, no; at least not immediately.
That means the foam is not an emergency, so you can relax.
However, the protein foam can create an environment that is harmful to your fish and eventually may even kill them. This can happen in many ways.
First, the bacteria in your aquarium love to feed on all things organic – protein foam is no exception. While this process is vital for nitrogen cycling – something needed in all aquariums – too much bacteria working on organic matter reduces the oxygen in the water, as the bacteria use the oxygen for decomposition.
If you are a prudent aquarium keeper, you should know that lack of sufficient oxygen is one of the most dangerous situations for your fish. Warm-water fish need at least 1.0 mg/L of dissolved oxygen, while cold-water fish require 2.5 – 3.5 mg/L. The last thing you want is for your fish to suffocate.
Protein-rich water is also a breeding ground for harmful bacteria and parasites, which can wipe out a large chunk of your fish population.
Lastly, protein foam really smells. Your fish may not mind this, but it would be obnoxious for the humans who have to stay in the same room.
Ways to Get Rid of Protein Foam in an Aquarium
Now that we have agreed that protein foam is bad and it has got to go, let’s see what we can do about it. You can do the following things to get rid of the pesky foam.
Clean the Aquarium
If you have put off cleaning your tank for too long, the foam is your cue to get to work. Even if you cleaned it not so long ago, certain events such as overfeeding or dead fish/plants may cause the organic waste to accumulate faster.
Make sure you clean the gravel of all organic debris, preferably with a gravel vacuum. And don’t forget to clean the filter as well.
A clean tank will not produce protein foam under normal circumstances, so your aquarium will be good for a while after you do this.
Remove any Dead Fish / Decaying Plant
If you are not in the mood for a complete cleanup, look out for any dead fish or decaying plant in the tank – protein foam is caused by organic waste, and dead fish or plants are a source of it. With any luck, you can get rid of the foaming problem without having to do a complete cleanup if you do this.
Make sure you look under every nook and cranny – it could be hiding anywhere in your tank, releasing the unsavoury froth to the surface.
Also, you could consider replacing the live plants with fake ones. It is easier to maintain but takes away the natural feel of your aquarium.
Use Protein Skimmers
If you are one of those aquarium owners who don’t like manual labor and want to automate everything, you can use a protein skimmer to get rid of the foam. This is more suitable for a saltwater aquarium – remember, saltwater is more prone to get protein foam.

As you’d expect with its name, the protein skimmer whisks the organic waste with air to create the unwanted foam, only this time the foam is collected by a removal cup, which can be emptied when full.
Besides getting rid of protein foam, the protein skimmer also oxygenates the water because of the water-air interface that it creates. That means you may not need a separate component for aeration.
Do Not Overfeed the Fish
You should know by now that organic waste is the root cause of protein foam, and fish food is a recurring source of that.
That does not mean you should starve your poor fish; rather, just don’t overfeed. Carefully calculate the amount of food your fish needs, based on the number and types of fish, and feed just that.
If you see a lot of leftover food after a feeding session, it means you are overfeeding. Try lowering the amount next time.
Summary
Protein foam is not a life-threatening emergency for your fish, but you should still deal with it because it can reduce the amount of oxygen over time, foster an environment for harmful bacteria and parasites to spread, and create a bad odor.
Use any of the above methods on how to get rid of protein foam in an aquarium to keep this unsavoury phenomenon from occurring in your tank. Thanks for reading.