Did you just set up a new aquarium with a beautiful wooden hardscape only to realize that a clear, mucus-like film has started to grow on it…
In general, newly placed driftwood, spider wood, or any other type of aquarium wood will start growing biofilm on its surface within the first weeks of being introduced into your aquarium. This biofilm is harmless to your livestock and will usually disappear over time.
I remember setting up my very first aquascape. After a few weeks, I noticed a clear film start developing over my hardscape. Being a new fishkeeper, I started to panic and stress…
I quickly realized that biofilm is completely harmless. So, I was panicking over nothing.
The good news is that it’s completely harmless there to your fish, invertebrates, and snails. Also, there are many ways to get rid of it, which I’ll cover below…
You’ll also learn that biofilm is actually a great food source for some of your livestock. I’ll share with you the best livestock to use if you want them to eat and clean the biofilm out of your tank for you!
But there are some potential dangers you should be aware of when it comes to biofilm…
Below, I’ll talk about why this grows, what causes it, different ways to remove it, and what to avoid!
Why Is There Biofilm Growing On My Aquarium Wood
Using a driftwood hardscape looks great in an aquascape and can create many benefits for your ecosystem…
You can grow live aquatic plants on it; it is a great place for beneficial bacteria to grow. It gives your tank a nice look and feel, and if you have a shrimp tank, it can provide a good place for your shrimp to gather and hide.
But putting a wooden hardscape in your tank can also bring about the growth of biofilm. It’s quite common for driftwood, especially in a new setup, to start forming this clear layer all over it, known as biofilm.
While biofilm is pretty harmless, it can cause issues with your tank if left untreated…
Now, let’s talk about what caused this film to grow in the first place.
What Causes Biofilm Growth
Basically, biofilm grows from dissolved organic carbon found in the water column…
This can be a long story about a complex breakdown of the exact chemistry of why biofilm may grow in an aquarium.
But that’s boring, and I like to try to explain things in an easy-to-understand way. So here’s a quick rundown of why this happens and what may cause it to happen…
When organic materials break down in an aquarium, they release compounds that particular bacteria and other microorganisms love to eat.
And once driftwood is in your tank, it starts the natural processes of releasing carbohydrates and other nutrients, creating the perfect environment for surface biofilm to begin forming.
Also, this slime, mold, and fungi clear-looking substance can start to form because of other reasons as well.
Here are the most popular reasons why biofilm may start growing within your tank and water surface:
- Any wooden hardscape like Cholla Wood, Spider, Mopani, etc.
- Nutrients leeching from nutrient-rich substrate.
- Decaying plants
- Having an uneaten food source in your tank water can cause biofilm growth.
- Sometimes, even the overuse of liquid fertilizers can cause it to grow. (But more commonly, you’ll get an algae growth from this instead of a biofilm one.)
Now that you know what causes biofilm to grow in your tank. Let’s talk about how to remove biofilm from your aquariums.
How To Remove Biofilm On Wood And Other Places
There are 3 popular ways to remove biofilm within your fish tank…
You can manually remove biofilm, use chemicals, and use certain fish species or other livestock to clean up the biofilm in your tank.
But the best way to deal with biofilm in your tank is to understand what is creating it in the first place. If it’s from an excess food source, then you’ll want to make sure to cut back on feeding. If it’s from a hardscape, then it’ll usually disappear over time once nutrients stop leeching out from it.
Now, let’s talk about the 3 most popular methods for treating biofilm
Manually Removing Bioflim In Your Aquarium
One of the easiest ways to deal with biofilm within your tank is by manually removing it with a soft bristle brush or an old toothbrush. (just be careful that there are no residual chemicals on your old toothbrush before using it.)
This is best done during one of the days you plan on doing a water change. What I like to do is have the siphon close by, and as I scrap away the biofilm, I’ll use the siphon to suck it up like a vacuum.
Also, most aquarists would agree this is a great opportunity to clean any algae, uneaten fish food, dead plants, or any other build-up of organic matter around your aquarium.
You can check out this post on how to maintain a planted tank if you want more information on aquarium maintenance.
Just make sure you do not leave any biofilm floating around or get on any live plants after cleaning…
Even though it’s harmless to fish. It can cause plants to melt and die if biofilm starts to grow on or around it. (I learned this lesson the hard way when I left some biofilm on the carpet of my aquarium)
Using Chemicals To Remove Biofilm In Your Fish Tank
I honestly do not recommend this at all.
Biofilm is generally very easy to deal with and will stop growing over time.
However, some people recommend using a light mixture of bleach or hydrogen peroxide to take care of biofilm in your tank.
I think this is going a little overboard, and there are easier and more natural ways to get rid of biofilm, like manual removal or using livestock to eat it.
Using Livestock To Remove Biofim Within Your Fish Tank
This is probably the most natural and easiest method to remove biofilm.
There are plenty of fish and other creatures who love biofilm and will eat up. That means you literally don’t have to do anything and just leave the cleaning up to your clean-up crew within your aquarium.
If you don’t have a clean-up crew, I definitely recommend starting one since it’s a great way to clean your aquariums naturally.
So, let’s talk about the best livestock to choose in order to remove biofilm.
What Eats Biofilm In A Fish Tank
You’ll be surprised at what kinds of fish will eat biofilm. I’ve even seen some of my guppies chow down on the biofilm on my hardscape…
But the most popular choices of fish and other livestock when it comes to dealing with biofilm are:
- Otocincilus Catfish: These are my favorite cleaners, especially in smaller tanks with other nanofish.
- Bristlenose Plecos
- Shrimps: Biofilm is a great food source for shrimps, and many people who have shrimp tanks grow biofilm on purpose in order to feed their shrimp tanks.
- Snails: They’re another great choice when it comes to a clean-up crew.
Things To Keep In Mind If You Let Biofilm Go Untreated
And like I’ve mentioned earlier in this post. Biofilm is completely harmless to most fish species and is even grown purposely for feeding in shrimp tanks and other livestock that love to nibble on it.
But this film also uses oxygen to grow. So, if left untreated, you run the risk of having low oxygen within your aquariums.
Biofilm can also start to build up on the water surface, which only increases the issue of oxygen in your tanks. But a little more surface agitation from a sponge filter or HOB filter can take care of biofilm on the water surface of your aquariums.
These are just a few things to keep in mind. But it shouldn’t be a problem as long as you don’t let this film start running rampant everywhere.
Final Thoughts On What Eats Growing Biofilm In A Fish Tank
So now, if you see a clear slimey substance start to form along the surface of a piece of driftwood, you know exactly what it is and how to deal with it.
Just make sure not to stress too much about it. It’s a completely normal part of any growing ecosystem. Usually, it will go away over time.
You have the option of manually removing it, or you can hire some shrimp or Otocinclus catfish in order to take care of it naturally.
Just be sure you feed them algae wafers or let some algae or diatoms grow so they have a steady source of food after they’ve taken care of all the biofilm for you.
I hope I was able to answer any questions you may have about this subject, and I hope to catch you on the next blog post!