Dosing Praziquantel (PZQ)

[christinna77]

@Jay Hemdal, I have a question about PraziPro in tank treatment vs. bath.

Let's assume:

• The fish has been properly acclimated for a few days at least, so no shipping stress
• The fish is active and eating well
• The fish has a mild fluke infestation

In this situation, would doing a PraziPro bath at 10 ppm for 3 hours (I've also heard of doing 7.5ppm for 6 hours - not sure which one is better and safer?), transferring the fish to a new sterile tank, and repeating this every 6 to 7 days each time, be more effective than in tank treatment?

My thinking is that:

• We don't have to worry about bacteria breaking down the medication too fast before it works if we already dosed the quarantine tank several times before
• We only need to deal with any unhatched eggs still on the fish, instead of the entire tank
• We can combine it with other treatments if needed, especially ones where dosing PraziPro at the same time is not recommended

Transferring the fish can be somewhat stressful, but it would only need to be done every 6 to 7 days.

That process is done in some cases.

However, it doesn't work for Neobenedenia flukes (one of the common species). They have sticky eggs and will get caught up when you move the fish from tank to tank. Just a single egg can restart an infection. Also, you would want to do this after the fish have been cleared of any potential protozoan diseases, as those kill fish much faster than flukes do, so should be treated first. finally, don't discount the stress of moving the fish tank to tank. The issue is not only the physical stress of moving the fish, but then, in many cases, the tanks the fish are being moved into are not cycled, exposing the fish to ammonia burns.

As you mention, the one benefit of this method is that it gets around much of the issue with prazi - degrading bacteria.

Another benefit (for large public aquariums) is that the amount of PZQ required is much less than in treating huge systems, so there is a cost benefit.

I usually use the 10 ppm dip for three hours with good aeration and temperature control.

Thank you for getting back to me, that makes perfect sense!

 

[gabesreef]

@Jay Hemdal
Hi so I have a reef tank and I was suspicious of my convict tang possibly having flukes so I dosed prazipro @85% to account for my rocks and sand. Now my question is when should I water change and re dose?

I’m a little confused based on what I read in this article the prazipro will be mostly degraded after like 24hrs. So should I water change at that point? Also how much water should I change? And then I guess I should repeat in 5 days?

 

[Jay Hemdal Verified Community Expert]

@Jay Hemdal
Hi so I have a reef tank and I was suspicious of my convict tang possibly having flukes so I dosed prazipro @85% to account for my rocks and sand. Now my question is when should I water change and re dose?

I’m a little confused based on what I read in this article the prazipro will be mostly degraded after like 24hrs. So should I water change at that point? Also how much water should I change? And then I guess I should repeat in 5 days?

With prazipro, the need for a water change is due to the solvent used. I generally advocate a 25% change. With regular prazi powder, I often don’t change the water at all. Repeat treatments are needed to control egg laying flukes because the prazi doesn’t kill the eggs - you need to try and time it so any eggs hatch out and then you redose to kill those, before they lay new eggs. That clean be tough to gauge though!

 

[gabesreef]

With prazipro, the need for a water change is due to the solvent used. I generally advocate a 25% change. With regular prazi powder, I often don’t change the water at all. Repeat treatments are needed to control egg laying flukes because the prazi doesn’t kill the eggs - you need to try and time it so any eggs hatch out and then you redose to kill those, before they lay new eggs. That clean be tough to gauge though!

Thank you for the quick response! Okay so I’ll do the water change after 24hrs?

 

[gabesreef]

With prazipro, the need for a water change is due to the solvent used. I generally advocate a 25% change. With regular prazi powder, I often don’t change the water at all. Repeat treatments are needed to control egg laying flukes because the prazi doesn’t kill the eggs - you need to try and time it so any eggs hatch out and then you redose to kill those, before they lay new eggs. That clean be tough to gauge though!

What time frame you do recommend for the second dose I’ve been reading 8 days?

 

[Jay Hemdal Verified Community Expert]

What time frame you do recommend for the second dose I’ve been reading 8 days?

5 days for gill flukes or the small skin flukes, 8 days for the large Neobenedenia flukes. If you don’t know which your fish have, go with 8 days.

 

[gabesreef]

5 days for gill flukes or the small skin flukes, 8 days for the large Neobenedenia flukes. If you don’t know which your fish have, go with 8 days.

I don’t know which I have the convict tang is white so it’s kind of hard to tell. He is flashing and was shaking his head. I will go with the 8 day method again thank you very much jay!

 

[jonnywink]

What time frame you do recommend for the second dose I’ve been reading 8 days?

5 days for gill flukes or the small skin flukes, 8 days for the large Neobenedenia flukes. If you don’t know which your fish have, go with 8 days.

@Jay Hemdal
If just doing a QT tank after the copper treatment finished, since it’s only a precautionary treatment, should I also use the 8 days after the first dose before I do the second dose?

 

[Jay Hemdal Verified Community Expert]

@Jay Hemdal
If just doing a QT tank after the copper treatment finished, since it’s only a precautionary treatment, should I also use the 8 days after the first dose before I do the second dose?

I’d go with 8 days for the second dose, but some guessing is involved here …. Many people run a third dose to be more effective in breaking the fluke life cycle.

 

[jonnywink]

I’d go with 8 days for the second dose, but some guessing is involved here …. Many people run a third dose to be more effective in breaking the fluke life cycle.

Thanks Jay.

 

[TylerHaworth]

Think I might have flukes, so grabbed some prazipro.

According to the 85% rule I’m at about 67.5 gallons water volume… That puts me at about 17mL of Prazipro, yeah?

 

[Jay Hemdal Verified Community Expert]

Think I might have flukes, so grabbed some prazipro.

According to the 85% rule I’m at about 67.5 gallons water volume… That puts me at about 17mL of Prazipro, yeah?

Yes - 16.85 ml. The 85% is just to try to take into account water displaced by rocks and sand.

Be sure the tank has good aeration.

 

[TylerHaworth]

Thanks Jay, you're a superhero.

Got an airstone + will take the cup off my skimmer.

Do I need to bypass my rollermat?

Water change and start skimming again after 24h then a second dose on day 8?

 

[Jay Hemdal Verified Community Expert]

Thanks Jay, you're a superhero.

Got an airstone + will take the cup off my skimmer.

Do I need to bypass my rollermat?

Water change and start skimming again after 24h then a second dose on day 8?

You may not need an air stone, as the skimmer will add good aeration.

I don’t know about roller mats, do you know what micron it filters down to? If less than 25 micron, I’d bypass it. You see, prazi isn’t really very soluble in seawater, it really disperses as a fine suspension, and you don’t want to filter that out.

Water change and restart skimming between 24 and 72 hours and redosing on day 8, but possibly a third dose 8 days after that.

 

[TylerHaworth]

Dosed this morning, hoping for the best.

 

[TylerHaworth]

Day 6 after Prazipro, I'm noticing my Royal Gramma flashing again after a few days break. This is normal or even to be expected from eggs hatching, correct?

 

[Jay Hemdal Verified Community Expert]

Day 6 after Prazipro, I'm noticing my Royal Gramma flashing again after a few days break. This is normal or even to be expected from eggs hatching, correct?

More or less expected, but you might want to dose now, do these new flukes don’t have time to lay fresh eggs. Three to four treatments may be needed to fully break the life cycle.

 

[TylerHaworth]

Will do, thank you Jay.

 

[TylerHaworth]

Just put second dose in, should I plan on doing the third dose in 6 days?

 

[Jay Hemdal Verified Community Expert]

Just put second dose in, should I plan on doing the third dose in 6 days?

And perhaps a 25% water change prior to that dose....