Eliminating Brown Diatom Algae

Brown algae per se isn't harmful to the fish and invertebrates in your fish tank. They may even consider the algae as food.

However, if left unchecked, brown algae can outcompete your plants. When that happens, your aquarium’s ecosystem is disrupted, and balance is thrown out the window. Decaying diatoms also contribute to poor water quality.

Besides, the sight of brown algae on a fish tank is anathema to a hobbyist. 

Luckily, tackling them isn’t rocket science. In this blog, we’ll share tried and tested methods on how to eliminate and prevent brown algae.

Identifying Brown Diatom Algae

Spotting brown diatom algae is pretty straightforward once you know what to look for. It shows up in tanks as a light to dark brown film coating surfaces. It's usually soft and easily rubbed off with your finger or a flat razor on the glass.

You can see what that looks like here on the glass in one of my tanks:

You'll often see it on glass, decorations, and even plant leaves. Unlike some algae, it doesn't form long strands or tufts.

Now, don't confuse diatoms with dinoflagellates. Dinos, as we call them, are usually more golden-brown and have a slimy texture. They're also tougher to remove and often give off a foul smell.

Diatoms, on the other hand, come off easily and don't stink.

If you're unsure, try the "finger test". Rub the algae gently; if it comes off easily and feels powdery, you're dealing with diatoms. After a few encounters, you'll spot the difference in no time.

What Causes Brown Diatom Algae Outbreaks?

Brown diatom algae outbreaks don't just happen out of the blue. They are caused by several factors:

First, excess nutrients, such as decaying organics, fuel their growth. These nutrients often come from fish waste, uneaten fish food, or plant debris.

Second, new tank syndrome is another common cause. Fresh setups have an abundance of silicates and fewer competing microorganisms.

Third, too much or too little light creates an environment where diatoms thrive.

Poor water circulation can create dead spots where diatoms set up shop. Inconsistent maintenance is also a factor. Skipping water changes or filter cleanings lets nutrients build up.

Lastly, imbalanced CO2 levels can hinder plant growth that would otherwise discourage the algae from taking hold.

Eliminating Brown Diatom Algae

Here are a few proven strategies to eliminate brown algae from your tank:

• Change around 20-30% of the water weekly. Changing water helps remove excess nutrients that diatoms feed on, keeping their growth in check.
• Clean the gravel during water changes to remove debris and uneaten food.
• Consider using phosphate reducers to lower phosphate levels, a key nutrient for diatoms.
• Ensure your tank has a balanced lighting cycle. Remember, diatoms thrive in low light. Aim for 8-10 hours of light daily. Use a timer to maintain consistency.
• Introduce algae-eating creatures that can help manage diatoms naturally. Otocinclus catfish and Amano shrimp are excellent choices. 

It usually takes 2-3 weeks to see significant improvement. Don't get discouraged if it doesn't clear up overnight. You might also have to do trials and errors to get things right.

Stick to this routine, eliminate the causes one by one, and you'll see results. 

Preventing Future Outbreaks

Prevention is still your best bet in keeping diatoms at bay.

Here are a few tips:

Stick to proper fish stocking levels. Overcrowding leads to excess waste and nutrients. Regular maintenance is non-negotiable: weekly water changes, filter cleanings, and gravel vacuuming.

Also, test your tank’s water parameters weekly and keep an eye on nitrates, phosphates, and silicates.

• Consider using reverse osmosis (RO) water to reduce silicates and maintain stable water chemistry. Since RO water may not be for every tank, try other silicate-absorbing media, like granular ferric oxide (GFO). 
• Proper lighting cycles and CO2 balance (if you're using it) are crucial.
• Don't forget about flow – good circulation prevents 'dead' zones where diatoms thrive.
• Ensure your tank has healthy plants – fast-growing plants like hornwort and water sprites can starve out diatoms.
• Lastly, quarantine new plants and decorations to avoid introducing silicates or other nutrients.

All these might seem like a lot, but as these habits become second nature, the reward is a healthy, diatom-free fish tank.

Takeaway

Battling brown diatom algae requires a multi-pronged approach, combining regular maintenance, nutrient control, and proper tank management.

Keep that consistent effort and the right strategies we described here.

You'll not only eliminate existing diatom outbreaks but also prevent future ones, ensuring a healthy and visually appealing aquarium for years to come!