The tea-colored water in your aquarium occurs very quick… Sometimes in just a few hours after you add chunk of driftwood. And if you’re a new aquarist, that might be seen as sign of failure.
You’ve purchased water conditioners and filters, but now your crystal clear aquarium water has turned into muddy brown. So what do you do? Scrub scrub scrub the wood till it’s white and dead…or else panic.
Why Driftwood Turns Aquarium Water Brown
Understanding Tannins in Aquarium Water
However, the truth is far less exciting. No need to panic, it’s not diseased, and it’s not dirty. It’s nature’s way of doing its thing: Tannins are a pigment that plants produce to protect against pests.
They’re called water soluble because they dissolves in water. When they come into contact with water (such as when your wood touches it), these natural chemicals is washed away. This simple reaction will change how you look at maintaining your tank, it’s no longer a mess to clean up but rather a science experiment.
Many plant contain something called tannins (oak barrels and tea leaves are two common examples). Tannins are polyphenolic compounds that binds to proteins and create a unique astringent taste in wine. Similarly, they stain the water.
They also provide a similar visual effect in an aquarium. That’s normal with some kinds of wood. Mangrove wood and Indian almond leaf are particularly infamous for this.
Relax. It’s not you, it’s the wood. And there’s nothing wrong with you or your tank.
Why Filters Don’t Remove Tannins
The wood is just doing its thing, which it has evolved to do. This leads some hobbyists to conclude that their filtration are bad. The reason?
They think that the color change must be due to poor filtration. That’s not true. Mechanical filtration (i.e., a canister filter, sponge filter) removes particulates.
Not dissolved chemicals. Therefore, your canister filter or sponge filter are functioning as intended. It won’t remove staining at a molecular level.
Why does this matter? Because it prevents you from spending money on upgrading your equipment when you don’t really need to. Yes, you may need to adjust your water chemistry.
Benefits of Tannins for Fish Health
Brown water isn’t necessarily a bad thing. For most tanks, the benefits of tannin far outweighs any visual downside. Tannic acid binds with and lowers the pH of the water and makes it softer.
This means your tank will look like blackwater rivers found throughout Southeast Asia and South America. Discus, betta, and many other fish species loves those types of waters. In addition to being soft and acidic, tannins contains weak antifungal and antibacterial properties.
That helps keep the tank healthy and can minimize stress on the fish. Brown water is a feature, not a bug for many tanks. Want more clear water?
Methods to Clear Brown Water
You can minimize the stain in several ways. One is boiling the wood before using it to draw some tannins out of the wood at the beginning. While this does lessen the impact somewhat, it usually doesn’t totally eliminate it.
Another trick people try is soaking the wood in a bucket of water that you change out over the course of a week. This will slow down the “shock” to your tank initially. It is a choice between convenience and clarity.
If you have activated carbon in your filter media, it’s also one of the best ways to clear tannin out of the water. Simply add some carbon and you’ll notice that it removes the color very fast. Standard carbon granules or many other commerical brands like Seachem Purigen work well for removing tannins.
What happens here is that the carbon takes in the dissolved organic compounds. Within a day or two the water clears up. Note: It’s a reversible option.
If you’d prefer to return the tannins, simply take the carbon out. Not all wood stains the same. Tropical wood is typically higher in tannins and therefore darker in driftwood form.
Choosing Driftwood with Less Stain
Popular woods includes spider wood and cholla wood. They also look rugged and natural. They also have a natural rustic appearance.
For less staining options go with highly processed or soak woods/roots. Leaves like catappa also impart some coloring, just not as much than large branches. It’s all about setting expectations at first through wise choice of decor.
Embracing Natural Blackwater Aesthetics
Embracing the brown doesn’t have to mean settling for it. It’s freeing when you realize there’s no need to keep up appearances of perfection. Nature isn’t clear most of the time.
Organic matter makes forest streams dark and cloudy. Embrace this reality in your tank. You’ll be amazed at how well your fish likes the dimmer, more natural light while they feel safe and secure in their new home.
That’s tough to measure psychologically, but very easily observed. In conclusion, do whatever you want. Make it brown if you choose.
Or make it clear. Either way has its advantages. Brown water looks natural and helps keep those fish healthy.
Clear water looks clean and shows off the fish. Neither one is wrong. Your tank is your ecosystem.
Decide for yourself how you would of like your ecosystem to look. Now take a gander at your tank. What do you think of the color change?
Is it muddy? Do the plants pop? Does the brown tint cover up any flaws?
Believe what you see. Embrace the stain or replace your filter media. Just know that the wood is sharing its story with you.
It’s up to you whether you want to hear it.
