Bryopsis Cure: My Battle With Bryopsis Using Fluconazole

Did Fluconazole Kill all of your Bryopsis?

  • Yes

  • No

  • I'm treating my tank with it now.

  • I love Bryopsis and I'm mad that everyone is killing it.

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Apr 6, 2016
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well happy to see your tank has clean again.. But since you do a treatment are you give 7tabs in every single day or does it only one shoot medication?
It is one shot

clark griswold

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May 1, 2018
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I’m on day 3 after dosing Reef Flux to kill Bryopsis. So far no bad effects on coral or fish or inverts. Chaeto seems fine too. I think im starting to see some white tips on the Bryopsis. Promising start.

I’ve been trying to get rid of this with water changes to no avail. Even took the rock out and scrubbed it clean with toothbrush. Just grew back. Really hoping this works.
Legendary Corals


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Aug 17, 2019
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I used it and followed directions and it didn’t kill it -__- so I gave up and just did plenty of water changes and it did the trick

Ray Laneville

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Jan 31, 2018
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New Bern, NC
I have a 90 gal and a 50 cube sharing the same sump/fuge about 30 gal. I had LOTS of bryopsis as I am reluctant to add chemicals at all. I gave in and bought reef flux, and added all 20 caps along with 4 emerald crabs. The recommended dosage was 1 cap per 10 gal but I wasn't going to save 3 capsules. I haven't seen the tanks yet today but as of yesterday the bryopsis is just about completely gone with the crabs working like crazy to mop up the remains. I've seen no adverse effects to fish, corals, cualerpa in the fuge, or pods.


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Aug 14, 2019
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If someone from this forum sends you a PM and trys to persuade you to not use this med,you should PM a mod(or pm me and I'll forward it to a mod) and let them know that you are being harassed. Many of the biggest names in the saltwater industry are now using this treament or have used it and you don't deserve to be harassed just becaused someone doesn't agree with it.

The Poll In This Thread is For Bryopsis Only not GHA,Turf,Bubble Algae or any other Algae

The 2 week treatment is for Bryopsis algae. For GHA,turf algae and bubble algae it may take as long as 4-6 weeks to kill.

GHA,turf algae,bubble algae are different than Bryopsis algae. Bryopsis algae will not return if you kill all of the Bryopsis cells unless you reintroduce it into your tank. The others can/will return once you stop treating your tank and perform water changes to remove the meds. Fluconazole doesn't change the conditions in your tank that allowed for the algae growth in the first place. Removing the meds just sends your tank back to the same conditons that you had before the treatment. If your using Fluconazole for something other than Bryopsis and wonder why GHA/turf/bubble algae comes back after you stop using Flucon, this is the reason. The poll is for Bryopsis algae not GHA/turf algae/Bubble algae or any other algae.People are killing other forms of algae with Flucon but if/when it comes back after they stop using it,they think that the treatment didn't work and vote no but it did work,they just removed the meds and sent their tank back to the same conditions as before the treatment.Once you perform water changes and remove the meds,you'll have to address the problems that you have in your tank that allowed GHA/turf/bubble algae to grow to start with.

Continuous Low Dose Usage

We've got systems that are running on a continuous 5-20%(depending on nutrient levels) of the original dosage of Fluconazole. These systems were treated with the orginal dose(20mg/gal) for the first 3-6 weeks(depending on amount/type of algae). There were a few tanks(out of over 30 tanks)that were treated twice from being covered in GHA. Bryopsis died in the first few weeks in each system that had it(or at least all that we could visually see).
After the 3-6 weeks we performed a 20% water change with an additional 20% water change the following week. We then dosed most of the tanks with 10%(2mg/gal) of the original dosage except for some higher nutrient systems that we dosed 20%(4mg/gal).We did have a couple ULNS that we dosed with .5mg/gal with varying results. (it's hard to match every single factor in these tanks)So what we decided was to go with 1-2mg/gal for the ULNS.Once a month we perform a 20% water change and replace the 20% flucon dose.As I've said,we have some systems that haven't had a water change in months.We'll have more details about that later.
So in all we ran 20mg/gal to kill the algae then 1-4mg/gal to to keep any GHA from returning.

Please read the Frequently Asked Questions(FAQs) located right after the pictures before you treat your tank.It should answer most of your questions and help you avoid some mistakes.

Fluconazole can be used as an antifungal med for fish and I haven't seen any adverse reactions from using it, but I just don't want anyone to come back and say that they killed their fish/corals or inverts and blame me. This was not my discovery as I am just following what some others have already done. If you try this it is at your own risk and don't shoot the messenger. :)

Okay so like I have said in another Fluconazole thread,I always inspect and QT everything before it goes into my tank. I had several frags in qt for a few weeks and all seamed fine. Before transferring them to my DT I brushed off what looked like regular green surface algae and thought nothing of it.Well after about a month all three frags had a healthy helping of Bryopsis growing on them.
I've had to deal with this years ago so I know what kind of a struggle it can be. I did not want to just sit around and hope this cleared itself up because I knew this could get really bad.I had a tank full of Bryopsis years ago and tried everything I could to get rid of it and it just kept spreading everywhere.
Finally after gallons and gallons (system was almost 400gls)of Kent Tech M I was able to melt the Bryopsis away but it was no picnic.

Now, after learning that Kent Tech M has changed and doesn't work anymore or is hit or miss now,I read about some people having success against Bryopsis using Vibrant.I tried Vibrant for a couple of months and it did damage the Bryopsis fern/fan leaves but it wouldn't kill it off completely. I know people say to just give it more time but let me show you what can happen when you give Bryopsis time in your tank.(BTW I'm not knocking Vibrant or @UWC I think he has been a stand up guy on this forum and some people have had great success using their products)

They did not call me the Bryopsis King for no reason........

It was like this across the entire tank. Notice for you tang lovers out there that mine had no interest what so ever in eating any of the Bryopsis.If they would have kept the rocks picked clean this would not have reached being the forest that you see.I have more pics but it's ugly and I think you get the picture.As you can see,this would be my reason for NOT wanting to wait too long on this.

Anyway this brings me up to using Fluconazole. After searching the good ole web I found that some people(some over seas) were using Fluconazole in a one time dose to kill off Byropsis. At first I thought that this was too good to be true.I mean most people were saying that their tanks were Bryopsis free in about 10-15 days give or take a few days. Then they started posting before and after pics and also saying that they had not lost any fish or corals!! OMG sign me up! I thought. Well after doing a little more research I found out that Fluconazole can be used to treat infections/diseases in fish and that the dosage I would need to use was considered somewhat "safe" for the fish so I placed an order..

There were two different dosages that were being used. One was 9mg/L and the other was 150mg/30L which is 5mg/L. I have 200 gallons of total water volume in this system which is 757L. So 757L x 9mg/L would be a dose of 6813mg. 757L x 5mg/L would be a dose of 3785mg.
I went with 4000mg so it was 20mg per gallon.
Everyone was seeing their results when using the lower dose so I went with the lower dose.

*Also note that if I were using Fluconazole to treat my fish for infections I would need to dose this same amount every 24hrs for no less than 5 days but not more than 10 days.

This made me feel somewhat better about using it because this would be a one time dose and not building up 5-10 times as much in my aquarium over the course of 5-10 days.

So let the battle begin!!

Before I dosed the tank I turned off my actinic lighting,changed my filter socks from 200 micron to mesh filter socks,turned off the UV channels on my Radions,removed my GFO/GAC filters and removed my skimmer cup.

I emptied 20 of the 200mg capsule in a cup of tank water and stirred for a minute or two.(throw away the empty capsules) Not all of the medication dissolved but that's okay. I then poured the entire cup in my DT in front of a powerhead.
Cloudiness went away after about an hour. Fish,corals and inverts didn't seem to notice any change at all.

I apologize in advance for my blurry pics as photography is not my strong suit.

Edit: I know some people don't like reading through entire threads and just want to see the results so I'll keep this first post updated with all the pics.

Before the treatment started...

Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

Day 7

Day 8

Day 9

Day 10

8 Months later and still no Bryopsis....

A big thank you to @stevo01 for his help on the FAQ for this thread.

Frequently Asked Questions (FAQs)

****This treatment seems to work best in well lit areas of the tank. Some people are noticing quicker results by adding light to the shaded areas of their tank.*****

Q: Will Fluconazole kill Bryopsis?
A: YES. Fluconazole will kill Bryopsis. There have been a couple of strains that seems to take longer to kill but if you have Bryopsis,it will kill it.It has also killed most forms of GHA although GHA takes longer to kill. Some tanks have needed another treatment to kill all of the GHA.Keep in mind that GHA can/will return in your system over time as you perform water changes and remove the Fluconazole. GHA shows up any time the conditions are right for its growth.This does not mean the treatment didn't work,only that the conditions were right for its return. Bryopsis however won't return in your system unless you didn't kill all of the Bryopsis cells during treatment or you reintroduce it into your tank through frags etc.

Q: How does Fluconazole work?
A: Fluconazole blocks the enzymatic pathway for the production of ergosterol. Ergosterol is essential for maintaining the cell wall integrity of plants. Ergosterol (ergosta-5,7,22-trien-3β-ol) is a sterol found in cell membranes of fungi and protozoa, serving many of the same functions that cholesterol serves in animal cells.

Q: Will Fluconazole kill anything else in my system?
A: So far Fluconazole has not killed anything other than bryopsis and GHA. Everything and I mean EVERYTHING else is unaffected.

Q: Where do I get Fluconazole?
A: There are many sources online.You can search for Fish Fluconazole and find it.

Q: How much Fluconazole do I use?
A: The suggested dose is one SINGLE dose in the amount of 20mg per gallon of water. There are reefers who are experimenting with using 10mg per gallon right now, but none with completing the 1st "round".

Q: Do I do a WC before treatment?
A: Yes. It would be a good idea as the treatment is for 14-21 days(some GHA can take around 4 weeks) and expect an increase in nutrients.

Q: How do I prepare the the medication?
A: I have noticed with the capsules it is very tough opening them without crushing the capsule. This is what I did. Use a razor blade and cut off the rounded end of the large outer half of the capsule. Then you can very easily pour the contents out into a glass of RODI water or tank water. The amount of water doesnt matter, but make it enough to be able to mix the med up. The med isnt very soluble, but mix it up best you can. Preferably dose at night when fish are asleep. Then pour the entire dose into the DT, or sump. Some have put it into their sump socks. I dosed directly into the DT.

Q: How long is the treatment?
A: 14-21 days.Some GHA may take a little longer.Longer treatments have been run without any problems so if you want to continue your treatment past the 3 weeks it will be fine.We have tanks continuously running on a low dose of Fluconazole for a year now with no ill effects.

Q: Do I remove my carbon?
A: Yes.

Q: Do I remove my skimmer cup?
A: Its suggested for at least the first few days if not the entire treatment remove your cup. If you pull your cup you may continue to run the skimmer, or turn the skimmer down as to not allow the skim to enter the cup. You do not want to remove the med.

Q: Do I take my ATS offline?
A: Yes. Completely sanitize it, and reintroduce it after all the bryopsis is 100% gone.

Q: Do I take my bio reactor offline?
A: No.

Q: Do I take my GFO offline?
A: No GFO will not remove the meds.It will also help to remove the po4 from dying algae.

Q: Do I continue to dose H2O2?
A: Yes. It will not interact with this med.

Q: Do I continue to dose Vibrant?
A: Yes. This SHOULD not interact this med. It may help to dose Vibrant as it will assist in NO3 export.

Q: Do I continue to dose colors, alk, calcium, and magnesium?
A: Yes.

Q: Should I change my lighting?
A: No.

Q: If I take my carbon reactor, or any other equipment off line/out of the tank, do I just put them back into the system after treatment?
A: No. Do not reintroduce the algae. It would be best to sterilize any equipment and throw away old media for reactors.

Q: Is it ok to take out my chaeto, or other algae's then put back after treatment?
A: No. this may reintroduce the algae. Leave the macros in the tank.

Q: Do I take my carbon reactor offline?
A: Yes.

Q:Should I stop using Purigen during treatment?

Q: Do I take my UV Sterilizer offline?
A: No. At first it was thought that the UV would break down the meds but further testing has shown that it doesn't seem to effect the treatment enough to remove it.

Q: Do I do a WC during treatment?
A: No. Unless it cannot be avoided and a WC needs to be done to save life.If you perform a wc then replace the meds with the fresh saltwater.

Q: Will Fluconazole kill my chaetomorpha or other beneficial maco's?
A: Some users have reported some macro algae loss during the treatment but most have not.We are not seeing any wide spread death in macros so it's more of a judgement call on your part.

Q: Will Fluconazole kill the parasitic algae known to burrow through LPS corals?
A: This is currently being researched.

Q: What other nuisance algae's will be killed by Fluconazole?
A: Fluconazole kills the green algae Derbesia also known as GHA. It seems that GHA takes longer to kill than the bryopsis but it still dies. It does not kill Bubble algae.

Q: When do I do a WC?
A: After treatment has completed you will go back to your normal running system. Do a WC as your NO3/PO4 levels may be high from a lot of dead algae.

NCreefguy and Stevo

This treatment has been a huge success.For so many years we have had to deal with this terrible algae. Well now we can finally say that beating Bryopsis is a reality. No more tearing down your tanks. No more endless hours of pulling and picking at this mess. Fluconazole has made the eradication of Bryopsis from our tanks quick,easy and painless.Please let everyone you know in the reefing community about this treatment. The more people who know,the better.

Thank you to everyone who has been and continues to help and contribute in the thread. R2R has the best reefing community around!!!

Special Note:
@Jose Mayo MD is the person from Brazil that discovered the actions of Fluconazole on algae. His discovery is the reason there are so many happy reefers today and will continue to be. Here are a couple of posts explaining his findings.

Thank you very much Mr. Mayo for your work,research and continued help with this treatment.You are a tremendous asset to the reefing community.

For your permanent systems running flucanazole, how do you handle proper fluc dosing while running your skimmer and media?

chris k.

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Mar 29, 2017
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Punta gorda
I have been adding vibrant around 3 months. But the last few weeks i have been getting something growing in my frag tank that looks like gha but could be bryopsis. I did introduce new corals about a month ago. My question is can i use reef flux with vibrant with no ill effects.

clark griswold

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Well I’ve completed a 3 week dose of reef flux. No water changes, no carbon, no skimmer.

All Bryopsis is dead.

No adverse effects on fish, coral, inverts, or chaeto.

Oddly my chaeto grew like it was on steroids over those three weeks. Never seen so much growth in chaeto. I think the Bryopsis was sucking up all the nutrients first but also taking my skimmer and water changes offline created excess nutrients. Either way an interesting observation.

Really glad I found this thread and decided to try the reef flux treatment. Thanks to all the contributors.


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Westchester, New York
FOLLOW UP: After using flux and killing my bryopsis originally. There were major losses to my sps corals in the reef. I lost about 6-7 mature colonies at the time and had months of ugly sps syndrome in my tank with those sps corals that actually did survive. However, I thought at least i was rid of the bryopsis for good.

UNFORTUNATELY its back. This time I am going to use Vibrant since it has been shown to have good results from alot of people here on R2R. I am just too afraid to use flux again and kill more corals.
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