Nutrient Spike with Fluconazole

[Adamantium]

Hi all! I have a fair bit of GHA I'm trying to get rid of, so I ordered some fluconazole. Do you guys know if I should expect a nutrient spike as the algae starts to die off? I expect so, but I want to see if anyone has experience.

Apparently, I'm not supposed to do a water change for 14 days after dosing, but I currently do ~15% every week, sometimes more often (trying to reduce levels from ~15-20PPM NO3 and ~.12 PO4).

I've plucked a bunch, but the majority is stubborn, and there's a pretty good amount of it, so I'm worried about a nutrient spike hurting corals, and perhaps even fish. I'll keep phosguard in, as I've heard a phosphate absorber is okay to have, but I'll remove carbon, and chemipure blue, as it has purigen in it, which you're supposed to remove. I also have biopellets that I started about 4 weeks ago. They haven't done much yet, but I'm thinking I'll keep them in, as well.

Any insight would be greatly appreciated! Thanks!

 

[Dkeller_nc]

This would be my choice if it was my tank. Discontinue all of the chemical absorbers; replace the Phosguard with GFO to avoid accumulating aluminum in the tank water. You don't say how big your tank is, but since you're using chemipure, I'm interpreting that it's pretty small (chemipure is very popular with nano keepers for some reason). If so, and assuming that you can match your new seawater's temperature and alkalinity to your tank, change 1/2 of the water. That will give you a reasonable knock-down of your dissolved nutrients before you start.

Then dose the fluconazole. BTW - it's not a bad idea to get a glass mason jar, fill it halfway with tank water, add the amount of fluconazole that will go into your tank to that, and then stir/mix it over the course of a couple of hours before you add it to the tank. In my experience, it's not that fluconazole is really insoluble in seawater, it's that it dissolves rather slowly.

Continue to feed your fish as normal, test for alk & ca and add 2-part as normal, and if you feel the need, continue the 15% change every week - simply replace the amount of fluconazole that you remove with the tank water. The reason I'm noting that you'll want to add the amount of fluc to your system that you removed with the water change is that for hair algae, fluconazole takes considerably longer to work than it does against bryopsis. I'd stick with the treatment regimen for 3 weeks to ensure that all of it is gone; premature removal of the fluc in the water potentially could result in a resistant strain of algae, which would be very bad indeed.

 

[Adamantium]

This would be my choice if it was my tank. Discontinue all of the chemical absorbers; replace the Phosguard with GFO to avoid accumulating aluminum in the tank water. You don't say how big your tank is, but since you're using chemipure, I'm interpreting that it's pretty small (chemipure is very popular with nano keepers for some reason). If so, and assuming that you can match your new seawater's temperature and alkalinity to your tank, change 1/2 of the water. That will give you a reasonable knock-down of your dissolved nutrients before you start.

Then dose the fluconazole. BTW - it's not a bad idea to get a glass mason jar, fill it halfway with tank water, add the amount of fluconazole that will go into your tank to that, and then stir/mix it over the course of a couple of hours before you add it to the tank. In my experience, it's not that fluconazole is really insoluble in seawater, it's that it dissolves rather slowly.

Continue to feed your fish as normal, test for alk & ca and add 2-part as normal, and if you feel the need, continue the 15% change every week - simply replace the amount of fluconazole that you remove with the tank water. The reason I'm noting that you'll want to add the amount of fluc to your system that you removed with the water change is that for hair algae, fluconazole takes considerably longer to work than it does against bryopsis. I'd stick with the treatment regimen for 3 weeks to ensure that all of it is gone; premature removal of the fluc in the water potentially could result in a resistant strain of algae, which would be very bad indeed.

Appreciate these insights! You're dead on; it's a 30 gallon tank with no sump. I'll continue to do ~4 gallon water changes each week, then, and just add about half a capsule after each one (one capsule treats 10G, IIRC).

I've done 3 15% water changes over the past 4-5 days, so I've basically already done what you suggested. I'll do one more for good measure, and then dose the fluconazole.

Have you ever used it yourself? The only thing making me nervous, despite all the positive reviews, is EAT SLEEP REEF saying it killed a few of his corals. I don't expect that, but it's definitely a bit concerning.

 

[Dkeller_nc]

I've used it with no losses. In my case, it was the ReefFlux brand.

 

[Adamantium]

I've used it with no losses. In my case, it was the ReefFlux brand.

I'm going to use Flux RX, but my understanding is that it's the same thing. Did you notice a spike in nutrients? I have quiiite a bit of GHA, so I'm most nervous about that aspect of dosing fluconazole.

 

[Dkeller_nc]

Yes, but it was mostly on the nitrate side; it roughly doubled my nitrates from about 5 ppm to 10 ppm. Phosphate remained unchanged, but there's a very simple explanation for that - I anticipated it, and changed the GFO in my reactor immediately before dosing. However, in my case the issue was bryopsis, and it's apparently far more susceptible to fluc than GHA. What little there was of GHA took almost 2 weeks to disappear (i.e., it died slowly), so I don't think there was much of a nutrient spike resulting from its disappearance.

 

[Adamantium]

Yes, but it was mostly on the nitrate side; it roughly doubled my nitrates from about 5 ppm to 10 ppm. Phosphate remained unchanged, but there's a very simple explanation for that - I anticipated it, and changed the GFO in my reactor immediately before dosing. However, in my case the issue was bryopsis, and it's apparently far more susceptible to fluc than GHA. What little there was of GHA took almost 2 weeks to disappear (i.e., it died slowly), so I don't think there was much of a nutrient spike resulting from its disappearance.

Awesome. This is great information. Really appreciate it! Have a good rest of your weekend!