Best solution for managing flukes while in copper treatment

[ss88]

@Jay Hemdal has previously mentioned not using praziquantel until copper is below 1.00 ppm.

What’s the best method for managing or treating flukes while actively treating for Cryptocaryon irritans.

I have considered the following.

1) doing water changes to lower copper to 1ppm then dosing praziquantel at 2ppm then again a large water change 24hrs later and raise copper back to 2.5ppm. Repeat 3 times at 1week intervals.

2) hypo salinity 1.009, no prior personal experience.

Currently managing Cryptocaryon irritans and suspected fluke infection on new acquisitions.

I read in
FISH DISEASE Diagnosis and Treatment Second Edition
By EDWARD J. NOGA, M.S., D.V.M.

Heterobothrium okamotoi and Neoeterobothrium
hirame are not affected at 11 ppt

So my thinking is that praziquantel would be required.

 

[Fish Fan]

I've said before, and I'll say now that we need an emoji for "interesting!"!

I'm following to see what Jay, Vette, and the other R2R fish medic guys say here.

Good luck!

 

[Jekyl]

https://www.reef2reef.com/threads/current-quarantine-protocol.825055/
Worth a look if you haven't seen yet.

 

[vetteguy53081]

@Jay Hemdal has previously mentioned not using praziquantel until copper is below 1.00 ppm.

What’s the best method for managing or treating flukes while actively treating for Cryptocaryon irritans.

I have considered the following.

1) doing water changes to lower copper to 1ppm then dosing praziquantel at 2ppm then again a large water change 24hrs later and raise copper back to 2.5ppm. Repeat 3 times at 1week intervals.

2) hypo salinity 1.009, no prior personal experience.

Currently managing Cryptocaryon irritans and suspected fluke infection on new acquisitions.

I read in
FISH DISEASE Diagnosis and Treatment Second Edition
By EDWARD J. NOGA, M.S., D.V.M.

Heterobothrium okamotoi and Neoeterobothrium
hirame are not affected at 11 ppt

So my thinking is that praziquantel would be required.

If you've done 30 days coppersafe, skip the hypo as its one or the other in which you have done the copper already, do a good water change and then you can proceed with Prazi dosing at 85% of the recommended and apply initial dosage known as an interval lasting for 8 days, do a water change and do one more 8 day dose interval
Use airstone with prazi as it does reduce both oxygen and appetite.

 

[Jay Hemdal Verified Community Expert]

@Jay Hemdal has previously mentioned not using praziquantel until copper is below 1.00 ppm.

What’s the best method for managing or treating flukes while actively treating for Cryptocaryon irritans.

I have considered the following.

1) doing water changes to lower copper to 1ppm then dosing praziquantel at 2ppm then again a large water change 24hrs later and raise copper back to 2.5ppm. Repeat 3 times at 1week intervals.

2) hypo salinity 1.009, no prior personal experience.

Currently managing Cryptocaryon irritans and suspected fluke infection on new acquisitions.

I read in
FISH DISEASE Diagnosis and Treatment Second Edition
By EDWARD J. NOGA, M.S., D.V.M.

Heterobothrium okamotoi and Neoeterobothrium
hirame are not affected at 11 ppt

So my thinking is that praziquantel would be required.

My advice to not use prazi until the copper level is dropped to around 1 ppm is cautionary. Sometimes, you need to run prazi and copper at the same time - there is just more risk to that. If you do that, you should use plain prazi powder, as Prazipro creates additional stress issues. The copper used needs to be Coppersafe or copper power.

As for your Noga reference, what page is it on? Neither of the species you listed are in his index.

Empirically, a specific gravity of 1.012 for 30 days eliminates Neobenedenia and Gyrodactylus. 1.009 controls Cryptocaryon as well.

 

[Miami Reef]

use plain prazi powder

What’s the solubility limit for prazi in seawater?

I used to dose general cure, which contains no solvent. It stays crystalized initially, but overnight it completely dissolves.

 

[Jay Hemdal Verified Community Expert]

What’s the solubility limit for prazi in seawater?

I used to dose general cure, which contains no solvent. It stays crystalized initially, but overnight it completely dissolves.

Solubility is very poor, I express it through a very fine mesh net, like a baby brine net. Even using a solvent, if you watch closely, you can see it immediately crystalize when you add the dissolved material to tank water - making a dust like plume.

 

[MnFish1]

It depends on whether your fish have Ich or Flukes or you're just doing a medicated quarantine.

if you're just doing a QT with copper and the fish are found to have flukes, you can treat with Prazipro per protocol, with extra oxygenation, and watching for symptoms. Or you can stop copper and do Praziproper protocol and do copper after. (This is the less optiomal choice)

If you're actually treating Ich and flukes (ie. the fish have the diseases) you can carefully use copper and prazipro together with extra oxygenation.

The general recommendation is not to mix medications, but if you document that the fish has 2 illnesses - it's ok to treat for both.

EDIT - just saw @Jay Hemdal gave his opinion - I agree with his comments. Additionally just to remind - one can not use copper nor hyposalinity for tanks with invertebrates, and hyposalinity does not cure all diseases (velvet being one example)

 

[ss88]

As for your Noga reference, what page is it on? Neither of the species you listed are in his index.

For me page 128. I have a digital copy.

 

[ss88]

I’m guessing the best approaches to treat with praziquantel then immediately a water change 18-24 hrs later.

I’ve seen wrasses become very stressed with dosing praziquantel concurrently. Unfortunately, I have some in this batch of fish.

 

[Jay Hemdal Verified Community Expert]

For me page 128. I have a digital copy.

Same as my hard copy. You can ignore that reference - those species of fluke are species-specific, you won’t see them on marine aquarium fish. Heterobothrium is only seen on oceanic puffers.

 

[vetteguy53081]

What’s the solubility limit for prazi in seawater?

I used to dose general cure, which contains no solvent. It stays crystalized initially, but overnight it completely dissolves.

Ive seen ethanol used as solvent for powder but not keen on its use for this. Other option used is dimethyl sulfoxide in liquid version

 

[Miami Reef]

Ive seen ethanol used as solvent for powder but not keen on its use for this. Other option used is dimethyl sulfoxide in liquid version

Yes. I spoke with Randy this morning about this.

I have DMSO, and I’m going to use it. It has a low toxicity profile and is a very effective solvent for praziquantel.

The carbon dosing effect should be significantly less with DMSO over Oxybispropanol, which PraziPro contains.

Bacteria will metabolize DMSO, so there isn’t any long term lingering effect that only large water changes can solve.

 

[vetteguy53081]

Yes. I spoke with Randy this morning about this.

I have DMSO, and I’m going to use it. It has a low toxicity profile and is a very effective solvent for praziquantel.

The carbon dosing effect should be significantly less with DMSO over Oxybispropanol, which PraziPro contains.

Bacteria will metabolize DMSO, so there isn’t any long term lingering effect that only large water changes can solve.

Agree on DMSO

 

[ss88]

Back story, praziquantel has been used in this system around 6 months ago, it’s a fish quarantine unit. However, since that time many water changes have been performed, it’s likely that less than 10% of all of the original water plus substrate is still present, the unit was also expanded from 200 gallons to nearly 600 gallons to manage larger volum of livestock.

Administered praziquantel at 2.2ppm at 7/29/25 - 10pm with lights out. The praziquantel was expressed through a fine mesh using 4 layers of women’s panty hose. Immediately noticed the presence of large body flukes beginning to relax and parasite body detach from the host, mouth anchor remained fixed to host. Assuming Neobenedenia and Benedenia.

Post 20hrs, some of the parasites have dropped from the host while others remained fixed. At the same time, I preformed a freshwater bath on some of the more infected specimens, immediately a large quantity of large body flukes dropped from the host, I didn’t examine the parasites under a microscope. But my assumption is that they are Neobenedenia and Benedenia as I can clearly see them with the naked eye.

So my assumption with the praziquantel treatment is that 1) it was not strong enough.
2) the dispersion crystallized immediately in the water column
3) was consumed by the bacteria to quickly
4) I under dosed. I was trying to be very conservative as I am administering this with copper. I tried to calculate the actual water volume within the structure, excluding tank walls and decor and substrates.

As these are newly imported specimens, currently 10 days under copper treatment, my concern is that placing them in hypo salinity runs the risk that there could be marine velvet.

I also have specimens that generally do not like hypo salinity, broomtail and H tusk wrasses.

What is the best path forward at this moment? I have the ability to separate certain specimens into different systems should it be required.

I was contemplating using freshwater dips on all of the fish for the next three weeks on a twice weekly basis to manage the flukes. This would get me though the copper treatment and allow me then to use hypo salinity.

I also considered using chloroquine phosphate at 40mg/gallon and dropping salinity to manage the flukes.

 

[MnFish1]

Back story, praziquantel has been used in this system around 6 months ago, it’s a fish quarantine unit. However, since that time many water changes have been performed, it’s likely that less than 10% of all of the original water plus substrate is still present, the unit was also expanded from 200 gallons to nearly 600 gallons to manage larger volum of livestock.

Great.

Administered praziquantel at 2.2ppm at 7/29/25 - 10pm with lights out. The praziquantel was expressed through a fine mesh using 4 layers of women’s panty hose. Immediately noticed the presence of large body flukes beginning to relax and parasite body detach from the host, mouth anchor remained fixed to host. Assuming Neobenedenia and Benedenia.

Usually a second and third dose is required.

Post 20hrs, some of the parasites have dropped from the host while others remained fixed. At the same time, I preformed a freshwater bath on some of the more infected specimens, immediately a large quantity of large body flukes dropped from the host, I didn’t examine the parasites under a microscope. But my assumption is that they are Neobenedenia and Benedenia as I can clearly see them with the naked eye.

How can you tell - this suggests your issue might not entirely be flukes IMHO. Normally with flukes you will not see parasites dropping - except for those that drop off in a FW dip. I have not experienced your result as quoted above - seeing flukes 'still fixed' on a fish

So my assumption with the praziquantel treatment is that 1) it was not strong enough.
2) the dispersion crystallized immediately in the water column
3) was consumed by the bacteria to quickly
4) I under dosed. I was trying to be very conservative as I am administering this with copper. I tried to calculate the actual water volume within the structure, excluding tank walls and decor and substrates.

You could be right with all. Some treatment regimens (including the one here) - recommend 2 doses and in some cases 3.

As these are newly imported specimens, currently 10 days under copper treatment, my concern is that placing them in hypo salinity runs the risk that there could be marine velvet.

I would continue your present protocol - copper and prazipro - unless there is some clinical issue with the fish

I also have specimens that generally do not like hypo salinity, broomtail and H tusk wrasses.

They will do fine - and don't worry about hyposalinity at this point. You just need copper and prazipro

What is the best path forward at this moment? I have the ability to separate certain specimens into different systems should it be required.

Not needed

I was contemplating using freshwater dips on all of the fish for the next three weeks on a twice weekly basis to manage the flukes. This would get me though the copper treatment and allow me then to use hypo salinity.

Freshwater drips are not a treatment or a cure. I would never do what you're suggesting. They are stressful. There is no reason for you to do hyposalinity - just repeat prazipro

I also considered using chloroquine phosphate at 40mg/gallon and dropping salinity to manage the flukes.

You could use chloroquine - however - just do one thing at a time - I.e. not doing hyposalinity with chloroquine. It may increase the toxicit of chloroquine

 

[MnFish1]

Back story, praziquantel has been used in this system around 6 months ago, it’s a fish quarantine unit. However, since that time many water changes have been performed, it’s likely that less than 10% of all of the original water plus substrate is still present, the unit was also expanded from 200 gallons to nearly 600 gallons to manage larger volum of livestock.

Administered praziquantel at 2.2ppm at 7/29/25 - 10pm with lights out. The praziquantel was expressed through a fine mesh using 4 layers of women’s panty hose. Immediately noticed the presence of large body flukes beginning to relax and parasite body detach from the host, mouth anchor remained fixed to host. Assuming Neobenedenia and Benedenia.

I think you were perhaps mistaking things here - it is extremely difficult to see flukes 'detaching'? Can you explain? Second - Prazipro does not act instantaneously

Post 20hrs, some of the parasites have dropped from the host while others remained fixed. At the same time, I preformed a freshwater bath on some of the more infected specimens, immediately a large quantity of large body flukes dropped from the host, I didn’t examine the parasites under a microscope. But my assumption is that they are Neobenedenia and Benedenia as I can clearly see them with the naked eye.

A picture here - with white light would be really helpful

So my assumption with the praziquantel treatment is that 1) it was not strong enough.

Why?

2) the dispersion crystallized immediately in the water column

?

3) was consumed by the bacteria to quickly

It is best to treat in a hospital tank - and as compared to in the regular tank. I think you're doing this - just mentioning it.

4) I under dosed. I was trying to be very conservative as I am administering this with copper. I tried to calculate the actual water volume within the structure, excluding tank walls and decor and substrates.

Probably underused. You can do copper and prazipro together. No need to be conservative.

As these are newly imported specimens, currently 10 days under copper treatment, my concern is that placing them in hypo salinity runs the risk that there could be marine velvet.

Just keep up with the copper and prazipro

I also have specimens that generally do not like hypo salinity, broomtail and H tusk wrasses.

What is the best path forward at this moment? I have the ability to separate certain specimens into different systems should it be required.

I was contemplating using freshwater dips on all of the fish for the next three weeks on a twice weekly basis to manage the flukes. This would get me though the copper treatment and allow me then to use hypo salinity.

I also considered using chloroquine phosphate at 40mg/gallon and dropping salinity to manage the flukes.

Just keep treating as you're doing IMHO. There is no reason to change - right?

 

[Jay Hemdal Verified Community Expert]

Back story, praziquantel has been used in this system around 6 months ago, it’s a fish quarantine unit. However, since that time many water changes have been performed, it’s likely that less than 10% of all of the original water plus substrate is still present, the unit was also expanded from 200 gallons to nearly 600 gallons to manage larger volum of livestock.

Administered praziquantel at 2.2ppm at 7/29/25 - 10pm with lights out. The praziquantel was expressed through a fine mesh using 4 layers of women’s panty hose. Immediately noticed the presence of large body flukes beginning to relax and parasite body detach from the host, mouth anchor remained fixed to host. Assuming Neobenedenia and Benedenia.

Post 20hrs, some of the parasites have dropped from the host while others remained fixed. At the same time, I preformed a freshwater bath on some of the more infected specimens, immediately a large quantity of large body flukes dropped from the host, I didn’t examine the parasites under a microscope. But my assumption is that they are Neobenedenia and Benedenia as I can clearly see them with the naked eye.

So my assumption with the praziquantel treatment is that 1) it was not strong enough.
2) the dispersion crystallized immediately in the water column
3) was consumed by the bacteria to quickly
4) I under dosed. I was trying to be very conservative as I am administering this with copper. I tried to calculate the actual water volume within the structure, excluding tank walls and decor and substrates.

As these are newly imported specimens, currently 10 days under copper treatment, my concern is that placing them in hypo salinity runs the risk that there could be marine velvet.

I also have specimens that generally do not like hypo salinity, broomtail and H tusk wrasses.

What is the best path forward at this moment? I have the ability to separate certain specimens into different systems should it be required.

I was contemplating using freshwater dips on all of the fish for the next three weeks on a twice weekly basis to manage the flukes. This would get me though the copper treatment and allow me then to use hypo salinity.

I also considered using chloroquine phosphate at 40mg/gallon and dropping salinity to manage the flukes.

Nobody knows exactly *where* the PZQ-eating bacteria live, but I'm pretty confident it is on the substrate. It also persists for a long time. Depending on how many doses of PZQ you ran 6 months ago, it could still be active enough to diminish the effects. I've dosed up to 4 mg/l in tanks with a history of being dosed.

I've seen that "waving Neobenedenia" before, and that is a sure sign that the active PZQ dose is too low.

In the end though, fully curing Neobenedenia with PZQ often just doesn't happen. It doesn't kill the eggs, and it has been demonstrated that a single egg can restart the infection. There is enough variation in timing for eggs hatching, that getting the doses correct is virtually impossible. Five doses, spaced 8 days apart sometimes doesn't even work.

In the end, I've just gone to hyposalinity for treating this - except for tanks with sharks and rays, or non-removable invertebrates.

 

[ss88]

Nobody knows exactly *where* the PZQ-eating bacteria live, but I'm pretty confident it is on the substrate. It also persists for a long time. Depending on how many doses of PZQ you ran 6 months ago, it could still be active enough to diminish the effects. I've dosed up to 4 mg/l in tanks with a history of being dosed.

I've seen that "waving Neobenedenia" before, and that is a sure sign that the active PZQ dose is too low.

In the end though, fully curing Neobenedenia with PZQ often just doesn't happen. It doesn't kill the eggs, and it has been demonstrated that a single egg can restart the infection. There is enough variation in timing for eggs hatching, that getting the doses correct is virtually impossible. Five doses, spaced 8 days apart sometimes doesn't even work.

In the end, I've just gone to hyposalinity for treating this - except for tanks with sharks and rays, or non-removable invertebrates.

Good way to describe them as "waving".

Am I better to switch to:

1) hypo-salinity now.
2) dosage again at 4mg/l, continued at 7 day intervals until i finish copper treatment then switch to hypo-salinity.
3) manage with freshwater dips every few days until copper is finished.

Slightly concerned about the risk of velvet, also some fish are sensitive to hypo-salinity.
If I did encounter velvet at low salinity the only treatment option would be chloroquine phosphate.

My immediate concern is controlling fluke populations.

 

[Jay Hemdal Verified Community Expert]

Good way to describe them as "waving".

Am I better to switch to:

1) hypo-salinity now.
2) dosage again at 4mg/l, continued at 7 day intervals until i finish copper treatment then switch to hypo-salinity.
3) manage with freshwater dips every few days until copper is finished.

Slightly concerned about the risk of velvet, also some fish are sensitive to hypo-salinity.
If I did encounter velvet at low salinity the only treatment option would be chloroquine phosphate.

My immediate concern is controlling fluke populations.

If you can catch fish for FW dips without damaging them, that’s a good way to hold Neo at bay until you can fully treat them after the copper.

You don’t need to go to full hypo like you do for ich. A specific gravity of 1.012 works. I don’t see fish have problems with that except sharks and rays.