Metronidazole

Humblefish

Dr. Fish
Metronidazole (Flagyl)

What It Treats
Internal parasites (flagellates), Brooklynella, Uronema marinum.

How To TreatMetro can be found as a stand-alone drug (e.g. Seachem MetroPlex, Hikari Metro+) or incorporated into a multi-purpose medication (e.g. API General Cure). When using 100% metronidazole powder, I dose 500 mg for every 20-40 gallons (80-160 liters). I typically start on the low end (500 mg per 40 gals), and then ramp it up to 500 mg per 20 gals by the 3rd or 4th dose. For brook & uronema, dose directly into a quarantine tank every 48 hours for 10-14 days. For intestinal worms, it is best to soak metro in the fish’s food. Use Seachem Focus to bind it to the food, and feed daily for up to 3 weeks or until symptoms (white stringy poop) disappear. My recipe for food soaking metro (and prazi) can be found below:

Using a shot glass:
1 scoop (~ 1/8 teaspoon) of medication
1 scoop Seachem Focus (this makes it reef safe)
1 tbsp food (preferably pellets or frozen food)
A pinch of Epsom salt to help expel dead worms/parasites
A few drops of saltwater or fish vitamins
Stir until a medicated food slurry has been achieved
Feed after soaking for 30 mins

Refrigerate or freeze any leftovers for future use

Whether or not metro is “reef safe” is a topic for debate. The general consensus is that while soaking it in fish food IS “reef safe,” dosing it directly into the water column IS NOT and should only be done in quarantine.

ProsCan be soaked in fish food, making it reef safe. However, Seachem Focus needs to be used to prevent the medication from leaching out. Also, it is a good idea to run carbon just in a case.
;)


Cons/Side Effects Certain fish seem to have a negative reaction/side effects to metronidazole; however this is rare.
 

JF47

New member
Hi, in this treatment with Metronidazole you say "1 tbsp food (preferably pellets or frozen food)". I currently have a few fish in QT that right now refuse anything other than flakes for some crazy reason. I usually feed frozen foods almost exclusively and I can't say I have ever had a fish that only wants flake. I can't get them to eat much else, but I need to treat internal parasites as one definitely has it. I want to add General Cure to their flake food while I transition them to other foods, but I'm concerned they won't get the proper amount of medication. Is it still 1 Tbsp of food if it is flake, or should it be some other number (perhaps by weight instead of volume)? On a related note, should I use something like alcohol to dissolve and bind it with the focus to the flake and let it dry out to create a dry batch to store and use, or would using Selcon and/or saltwater be enough?
 

Humblefish

Dr. Fish
@JF47 Pellets would be better as those are more porous and thus would absorb more of the medication. Whenever I’ve tried using flake w/meds, it just gets all mushy and the fish refuse to eat it. But it’s worth a shot to try.

Dosage would be the same (1/8 tsp of medication per 1 tbsp of flake), and no need to use alcohol as metro will dissolve in a few drops of SW after about 30 mins. We don’t want to get the fish drunk. ;)
 

JF47

New member
@JF47 ...Dosage would be the same (1/8 tsp of medication per 1 tbsp of flake), and no need to use alcohol as metro will dissolve in a few drops of SW after about 30 mins. We don’t want to get the fish drunk. ;)
Thank you! I got the idea for disolving with alcohol here http://www.hikariusa.com/articles/medicatedfeed.html You would mix it in and then let it dry off so as to not introduce it to the fish much (if any). I am also concerned it will get mushy, but I'll try it tonight and see. Thanks again!!
 

Humblefish

Dr. Fish
Thank you! I got the idea for disolving with alcohol here http://www.hikariusa.com/articles/medicatedfeed.html You would mix it in and then let it dry off so as to not introduce it to the fish much (if any). I am also concerned it will get mushy, but I'll try it tonight and see. Thanks again!!
That's interesting about letting the alcohol evaporate. I may try it. Let us know how you get on with using flake food.
 

JF47

New member
...Let us know how you get on with using flake food.
A quick one day update on using flake. I used flake, Focus, and GC mixed in a small container and shaken to mix. I then added a fair amount of Selcon, shaking between drops, to wet the flake and shook it around a bit more to get everything binding. It was fairly damp and clumpy, so I tried a quick low heat in the oven to dry it, but that was taking forever. I switched to just a few seconds in the microwave with paper towels top and bottom which worked much better. I broke it up from the clumps afterward and stored it in the container in the fridge. I probably went too long on the microwave (cooked it a bit and the smell wasn't exactly great), and I hope that didn't impact the potency of the medication, but nothing I read said heat would be an issue for it. If you think heating it could be a problem then I will have to try another way I suppose. I don't have access to the alcohol that link recommended (at least not without ordering online, paying a lot and waiting a week).

All that said, I fed it to them this morning and they all ate it without much trouble except for pieces where I had not really broken it up enough for them first.
 

Humblefish

Dr. Fish
I probably went too long on the microwave (cooked it a bit and the smell wasn't exactly great), and I hope that didn't impact the potency of the medication, but nothing I read said heat would be an issue for it. If you think heating it could be a problem then I will have to try another way I suppose.
Heat and sunlight can degrade medications whilst they are still in powder form. I store all my meds in a freezer to prolong their shelf life.
 

Corey

New member
With Metroplex dosing in water. Do you do a water change after each 48 hour treatment, for 14 days? Treating as a precautionary. Thanks
 

Humblefish

Dr. Fish
With Metroplex dosing in water. Do you do a water change after each 48 hour treatment, for 14 days? Treating as a precautionary. Thanks
It's not necessary to do a water change before each metro dosage. Most of the medication will have dissipated out after 48 hours anyway. I would do a large water change at the end just to remove any lingering residuals.
 
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