What Is The White Stuff Growing On My Aquarium Wood?
Mangrove wood is popular in reef tanks because it improves water quality, provides a home for marine life, and adds to the aesthetics. If you have noticed unsightly white fuzz growing on the mangrove wood after adding it to your aquarium, before you panic and start using chemical treatments, let’s go through what it could be and whether you should be worried.
The Most Common Cause Of White Fuzz On Aquarium Wood
The cause of a white coating on aquarium wood, like mangrove root, is normally a biofilm formation. Biofilm is a complex community of microorganisms that form a slimy, protective layer. While the white growth may look alarming, biofilm is a sign that your reef tank is starting the natural biological process.
The appearance of biofilm occurs when organic materials like mangrove root is submerged in saltwater. In response, the aquarium wood slowly releases organic compounds that allow the microorgansisms found in biofilms to feast on. As the microorganisms munch on the nutrients, they rapidly multiply, creating the white coating that can appear slimy and gel-like in texture or wispy and cotton-like.
Why Does Mangrove Root Attract Microbial Populations?
Aquarium mangrove root wood is especially susceptible to biofilm formation because of the following factors:
-
Mangrove root wood contains natural organic compounds that microorganisms love.
-
The porous and irregular surface of mangrove root wood provides nooks and crannies perfect for fungi and bacteria to colonize.
-
Mangrove root wood is added during the cycling process. A newly established reef tank is still finding its biological balance, making it the perfect time for microorganisms to multiply and cover the wood in a biofilm.
-
The warm and nutrient-rich water found in saltwater aquariums can accelerate microbial growth faster compared to freshwater aquariums.
Is Biofilm Harmful For Reef Tanks?
The good news is, most biofilm is harmless to fish, corals, and invertebrates, and blooms typically disappear wthin a few weeks. Some biofilm is actually beneficial, serving as a natural food for marine organisms and supporting biological processes in newly established reef tanks.
However, you should keep in mind the following:
-
Water Parameters: Biofilm (and any organic decomposition) should be closely monitored to check that it doesn’t affect water quality.
-
Coral Health: Excessive biofilm in aquariums can block light or affect water flow.
-
Aesthetic Issues: Biofilm can be unsightly to reef displays.
-
Harmful Growth: You should know the difference between normal biofilm and harmful cyanobacteria that need to be eliminated. Biofilms are white or gray, while cyanobacteria are typically blue-green and slimier than biofilm coatings.
Biofilm Life Cycle In Reef Aquariums
Biofilm follows a pretty simple life cycle:
-
Initial Appearance: Typically 3-7 days after introducing mangrove root wood to a reef aquarium.
-
Peak Growth: Usually takes 2-3 weeks.
-
Gradual Population Decline: As nutrients are consumed from the mangrove wood, the beneficial bacteria is established and the biofilm population starts to deplete.
-
Disappearance: Most biofilm colonies will naturally disappear over a couple of months.
Many hobbyists have found that in established reef tanks with robust biological filtration systems, the biofilm cycle tends to be shorter than in new setups.
How To Manage Biofilm In Reef Aquariums
If the biofilm growth is extensive, there are ways to safely manage it.
Manual Removal
The simplest solution is to remove the mangrove root wood and gently scrub the biofilm off the wood using a soft brush and rinse the wood before placing it back into your aquarium. Be careful not to scrub the wood too aggressively as it could release more organic matter into your reef tank.
Pre-Treating Wood
Curing and preparing mangrove root wood before adding it to your reef tank can greatly reduce biofilm formation.
-
Place the mangrove wood in a separate container with saltwater and change the water every few days until the biofilm is reduced. This process usually takes several weeks.
-
If you have a separate tank, you can cure the mangrove wood by placing it in there with a strong water flow and running a protein skimmer for several weeks before adding it to your display tank.
Aquarium Cleanup Crew
Some reef-tank safe invertebrates and fish can help manage biofilm growth. These include:
-
Creith and Astrea snails
-
Reef-safe hermit crabs
-
Some species of blennies
Biofilm Vs Other Aquarium Growths
Biofilm
-
Color: White/grayish
-
Texture: Slimy or cotton-like (uniform coverage)
-
Concern Level: Low
-
Treatment: Usually resolves on itself, gentle manual removal is best
Cyanobacteria
-
Color: Blueish-green, sometimes red
-
Texture: Slimy
-
Concern Level: Moderate to high
-
Treatment: Reduce nutrients, improve water flow, and manual removal
Diatoms
-
Color: Brown
-
Texture: Dusty coating
-
Concern Level: Low to moderate
-
Treatment: Usually temporary, improve water quality, and manual removal
Dinoflagellates
-
Color: Brown or golden
-
Texture: Bubbly or slimy
-
Concern Level: High
-
Treatment: Reduce nutrients, improve water quality, and use chemical intervention
When To Be Concerned About White Growth On Aquarium Wood?
As mentioned, biofilm is not generally a cause for concern in a reef tank, however, many reefers may want to take action. Here are the common reasons why:
-
If the biofilm starts showing unusual colors
-
If the biofilm persists longer than 2-3 months without the population reducing
-
If the biofilm is developing a foul smell
-
If your water parameters are declining
Summary
For most reef hobbyists, the simple solution to white growth on mangrove root wood is patience, as its usually natural biofilm which takes time and patience to naturally recede. However, you should know the clear differences between biofilm and harmful bacteria like cyanobacteria.
If you are unsure if your white fuzz is harmless or something to worry about, or you would like more advice about removing it from your aquarium, contact the Reefco Aquariums team today!
