A Holiday Visit Turned Reef Tank Rescue: Tackling Bryopsis Algae

The holidays are a time for gathering with loved ones, sharing meals, and catching up on life. This year, however, my family visit included an unexpected task: dealing with a persistent algae infestation in their reef tank. If you’ve ever battled bryopsis algae, you know it’s no easy feat. While I came prepared to exchange gifts and stories, I ended up donning my "reef-keeper" hat to help restore their tank to its former glory.

The Problem: Bryopsis Algae

Bryopsis is one of the most stubborn algae species that can infest a reef tank. It’s a feathery green menace that thrives under various conditions and is notorious for being unappealing to most herbivores like snails, tangs, and other clean-up crew members. The usual suspects snails and grazing fish wont eat it. The algae kept spreading, overtaking corals and threatening the overall health of the tank. What made this tricky to identify was that it was brown. Briopsis is usually deep green. So I thought it was dinos because it was deep brown and looked slimy. 

Interestingly, my first thought was that poor water parameters might be fueling the algae, but after testing, everything was well within range:

Salinity: 1.025

pH: 8.2

Nitrate: 0.8 ppm

Phosphate: 0.12 ppm

Alkalinity: 10.6 dKH

These levels were ideal for a reef tank, so I figured it was dinos that could be sucked up by doing a water change.

Step 1: Manual Removal

As soon as I touched it I knew it wasnt slimey dinoflagellates.  It felt like a brillo pad and when I riped off a chunk there it showed its green menacing self, bryopsis.  The first step in dealing with bryopsis is good old-fashioned manual labor. I rolled up my sleeves, grabbed some tweezers, and removed as much of the algae as I could. This step is crucial because it helps reduce the algae's biomass, making subsequent treatments more effective. While it’s impossible to get every strand manually, even a partial cleanup can significantly improve the tank’s appearance and overall health as seen in the before and after picture.

Step 2: Fluconazole Treatment

Once I removed as much bryopsis as possible, it was time to bring out the big guns: fluconazole. This antifungal medication, commonly used to treat yeast infections in humans, has gained popularity in the reefing community for its effectiveness against bryopsis. It works by targeting the algae's cellular processes, causing it to die off over time.  Its easily obtained from local fish stores or next day from Amazon.

I calculated the correct dosage based on the tank’s water volume and added the fluconazole. It’s important to remove activated carbon and other chemical filtration media before treatment, as these can absorb the medication and reduce its effectiveness.

Step 3: Patience

Fluconazole isn’t an instant fix; it typically takes about two weeks to see results. During this time, I advised my father-in-law to keep an eye on the tank, maintain normal water parameters, and avoid major water changes that could dilute the treatment. In some cases, a second treatment may be necessary if the bryopsis isn’t entirely eradicated after the first round.

The Aftermath

I reassured him that with patience and consistency, the tank would be bryopsis-free in no time. In addition to the treatment, I encouraged him to review their tank’s nutrient levels, lighting, and flow to prevent future outbreaks. Bryopsis often thrives in tanks with excess nutrients or imbalanced conditions, so addressing these factors is essential for long-term success. However, it usually comes in on new coral frags so proper quarantine can avoid it all together.

A Lesson in Problem-Solving

Helping my family with their reef tank was an unexpected but rewarding challenge. It reminded me that the holidays aren’t just about traditions—they’re also about lending a hand and sharing knowledge. If you’re a fellow reef-keeper, don’t hesitate to pass on your expertise to others. Whether it’s battling algae or troubleshooting equipment, your experience can make a world of difference.

Here’s to a Happy New Year, healthy tanks, and the satisfaction of overcoming a reefing challenge! Contact Aquatic Utopia for your system design or maintenance needs today!