Looking for Fluconazole advice

[CornishCrustyCorals]

So I treated my tank just over a week ago as I had A LOT of bryopsis and a small amount of GHA

Its working and I have noticed the GHA almost completely gone and the Bryopsis is definetly thinning out

My plan was to not do a water change for at least 2 weeks and ride it out knowing I would get some of the ugly algaes as all the excess nutrients from the dead algae getting released into the tank. Then I had a brain fart and I went and did my routine water change. So I have removed about 1/5th of the water and replaced with new SW.

Now I am concerned as I have probably removed some of the medication that was in the water. Am I able to add more fluconazole safely? if so how much? I dont want to kill anything and on initial dosing my nems and a couple soft corals were not looking great and have only just started looking ok

 

[Courtney Aldrich]

I wouldn't dose any more. A 20% change in concentration is not much, so I would expect the remaining fluconazole to maintain sufficient activity, but I doubt you would do any harm by adding 20% more fluconazole. The recommended dosing of fluconazole for treating bryopsis has not been rigorously determined and I'm sure the dose you used is likely in excess of what is needed. Fluconazole has pretty good stability in ambient conditions (room temperature, ambient light), but is degraded by UV, so hopefully you're not running UV and have removed your GAC, which will absorb fluconazole. Unlike many other repurposed drugs used in saltwater (chloroquine, fenbendazole, praziquantel, etc...) which are very lipophilic and will bind to and concentrate in organic matter (i.e. fish, corals and algae), fluconazole is pretty well behaved and I expect well distributed in the water column.

 

[CornishCrustyCorals]

yeah no UV, I have enough fluconazole left to do a full treatment of the tank again so I'll ride this one out then and if the bryopsis starts to look like its making a comeback I'll do a water change then try again.

One thing I can say is it works really well!

 

[Courtney Aldrich]

That's great to hear. The use of fluconazole for treating bryopsis was pioneered by Dr. Jose Mayo (see his post here: http://www.reefcentral.com/forums/showthread.php?p=25415333). Fluconazole works because it inhibits a unique lipid known as ergosterol in the algae cell wall that is normally found in fungi (fluconazole is an antifungal agent).