It is also 100% ‘legal’ unlike some of the grey market compounds. ‘Prazi’ has been sought after for years as the fluke treatment of choice but has been unavailable in our hobby due to expense, until NOW.

As a preventative, we recommend treating once a year in early Spring.

Prazi is available in 50 gram bottles (Treats 5,110 gallons) and 100 gram bottles (treats 10,220 gallons).

Pros
Safe, one dose, no water changes, very effective, and no reef or filter effects!

Cons
Slightly more expensive that the more common, more dangerous preparations which require multiple doses, water changes, or which may be hazardous to Discus, Goldfish, Catfish etc..

Frequently Asked Questions

Q: Hi! I will be treating my pond with Prazi. Do I need to remove the activated charcoal from my filter? If so, for how long? Also, I have a resident frog that lives in the pond. Will the Prazi harm him? Thank you for your time and responses.. Dale D. New Jersey

A: Great questions - Yes, remove carbon, it effectively removes the Prazi. Too, frogs and amphibians are unaffected by the Prazi, so they're safe. Thanks - Doc Johnson

Q: Will Prazi kill leeches?

A: Nope. Sorry it won't. There's so much that won't kill Hirudinea / leeches. This is something we want to work on at KoiLab. So far, nothing but enormous doses of organophosphates. I am sure there's something better, I will keep trying. ~ Doc Johnson - Pondrx.com

Q: Can Prazi be use with goldfish? ranchus and lionheads? Is it okay to use Prazi if there is salt in the tank?

A: Prazi is safe with all species of fish. Including Orfe, Tench and Rudd. Fancy goldfish are part of the reason we developed Prazi, since Supaverm is toxic to goldfish. So, Prazi would be the flukicide of choice for Goldfish of the types you listed. Prazi and salt are safe and effective together and neither remedy requires any water changes. ~ Doctor Johnson

Q: Can you over dose with praziquantel? I will not be able to figure the exact gallons of water in the pond.

A: Unless you were rich, and superbly careless, you would not be able to overdose with Prazi. If you overdosed by ten times you still would not hit any threshold of toxicity to the fish. So, practically speaking, I would tell you that you have no realistic worries at all. ~ Dr. Erik Johnson

Q: How soon after I've used Hydrogen Peroxide can I treat with prazi?

A: Immediately. Praziquantel is not denatured by hydrogen peroxide and does not represent any threat to fish when used in combination by intention or by accident. ~ Dr. Erik Johnson (koivet.com)

Q: I have used a combination of Prazi and Proform-C to treat my pond. The Prazi says to leave it in long enough to work, how long? The Proform-C says to do three treatments, one a day with a 25% water change each day for best results. If I do not do the water changes to keep the required amount of Prazi in the pond will I cause the Concentration of Proform-C to get to toxic to the fish.

A: Prazi has been tested under a lot of conditions and it's odd, flukes and certain other disease organisms have been cleared in as little as two hours by some work, and two days by other testers. So, NO water changes would be the "best bet" unless you could confirm everything with a microscope.

Proform C was designed "weak" by intention. So, using it according to instructions without water changes only means you should watch the fish for signs of "not enough oxygen in the water (piping at surface) or stress on the skin (pinking) which indicate the Formalin (Proform C) is either consuming oxygen in the tank or burning the skin, which would then MANDATE a water change despite the jeopardy to the Prazi regimen. ~ Dr. Erik Johnson.

Q: Hi. I want to treat gill flukes in a freshwater aquarium that has lots of shrimp, clams and snails in it, all of them ornamental or at least useful and worth keeping. Will praziquantel harm these invertebrates (everyone tells me flukes are invertebrates and you can't kill them without killing all invertebrates!). Also, I'm told that shrimp are an intermediate host for gill flukes. Does this mean they can escape prazi while they are in the shrimp (assuming, of course, that the shrimp don't die)? Finally, do you have smaller quantities of prazi for aquarium use (one gram would be plently)? Thanks

A: Shrimp are not an intermediate for Flukes, you should worry about the one who told you that. A monogenetic trematode (fluke) is just that: Monogenetic meaning it has no intermediate host. So don't worry about the shrimp. It's a safe bet that anything that would kill the Flukes would also hammer your invertebrates, however, Prazi is safe with SOME invertebrates. This is the testing we want to accomplish at KoiLab.com - Anyway - you should remove the fish for 2-3 weeks and treat in a separate system, OR consider a small biological test on ONE clam, ONE shrimp, ONE snail, in a container - to see whether the product you're considering will cause harm to them.

A smaller gram-size Prazi is going to be available within the month!

Doc Johnson

Q: Have had a recent and serious problem which we have finally determined is flukes. We were advised to add Dimilin, which we did two days ago, enough to treat our 5,000 gallon pond. How soon can we add Prazi? Thank you.

A: WOW! People should know so "NOW HEAR THIS" Flukes do NOT respond to Dimilin - AT ALL.

Prazi can be used WITH Dimilin and this makes a wonderful shotgun remedy to intercept Flukes, Anchor Worm and Fish Lice in one fell-swoop. So, it's good. Prazi is very safe. So is Dimilin and the other chitin synthesis inhibitors like Anchors Away and Express IDI.

Doc Johnson

Q: Hello Doctor, I have Program in the water right now for Lice, and I'd like to know if it's okay to add Prazi simultaneously? As both are nontoxic, I'd assume so, but I just want to be sure. Thanks!

A: Hello, Prazi and Program (lufenuron) are compatible. You would have a combined spectrum of activity [and safely] against Anchor Worms, Fish Lice and Flukes. That is all. But no health hazards to the fish or filtration. ~ Dr. Erik Johnson

Q: Would prazi work on argulus?

A: It shouldn't, however, I have not tried it.

Doc Johnson

Q: Hi- Thank you for overnighting the Prazi to me. I added it as described yesterday around 5pm. It's now about 8:30 am here and the two larger koi are still spitting out their food. I was just wondering if this is normal. Thanks in advance for your help! Lynn

A: No problem - Thanks for your patronage, it's appreciated more than you know. As far as the fish still spitting - YES< food spitting is a common result of Fluke infestation, but there are two issues:

1) Are we sure it's "just" flukes?

2) If it is Flukes, the gill changes which make the fish "spit" would take four to five days to resolve after clearance of the flukes. So, even if you're right on in the diagnosis, it's not been long enough to see clearance of that symptom.

Good question!

Doc Johnson

Pondrx.com

PS: Prazi has not been associated with any illness or untoward reactions except where people mix it with stupid medicines which oughtn't be used in fish ponds to begin with, like Rid Ich.

Q: I just did a 12 hr. treatment in my pond of Potassium Permanganate. The instructions were to bypass the filter during this procedure.and after a 40% water change to start the filter again. My question; If we had flukes or other harmful parasites in the pond wouldn't they also be present in the filter to be reintroduced back into the pond?

A: That is correct. That is why the instructions guide you to do more than one treatment. It is statistically impossible for the parasite to 'hide' in the filter twice, and impossible for the parasite to 'continue' to hide in the filter past the sequential treatments because without a host, they (parasites) will die.

So, the sequential treatments would require a 'hider parasite' to live without a host, or; even less likely, to get out of the filter, feed on the host, and return to the filter in time to miss the second dose of PP - "As IF" it had a sentient cortex on it's brain. (Which thankfully it does not).

Good question, though!

Doc Johnson - Pondrx.com

Q: Greetings Doc Johnson! Assuming a system has been dosed properly, what is the Prazi's efficacy period? A week? month? or like, salt until you remove it? Thanks, J. K. White

A: Prazi will reside in a system at least three days. I can tell you that because when praziquantel [Droncit] was really expensive, like $7 per pill from the Vet, you could set up a tank and deworm Discus with it for about three to four days on the same tank load. Past that, no one thought the stuff hung around much. So, let's go with three to four days 'residence' -While it's interesting to note that repeat dosing is not needed for flukes with Prazi, perhaps because it permeates and stops the developing egg or embryo like no other medication we have.

Q: Is it possible that Prazi is, or will become available in a smaller amount, say for the average, indoor 55-gallon ornamental goldfish aquarist? Thanks for your time. RR

A: It's here. There's a new Prazi container that's about thirty five dollars and will last you a long time in tropical and goldfish facilities.

Doc Johnson

Q: Is it safe to use Prazi with Anchor's Away together or do you have to use one then wait a week, then treat with the other.

Thank you,

Alan

A: You can use Prazi and Anchors Away together. Neither one is toxic even at gross overdose. Neither one requires a water change, and their spectrum is different. Very different. So, using them together is a fine choice. HOWEVER unless you see a parasite attached to the fish, Anchor's Away has limited use for you. It's just for Anchor Worm or Fish Lice, both of which you can see with the unaided eye.

ELJ

Q: What are the regulations/laws for prazi?

A: Praziquantel is a prescription drug except when used on ORNAMENTAL fish. Then, it is generally regarded as safe, it's spectrum is well known and accepted, it is not regarded as harmful, and when properly labelled (not for use in food fish, not for human use, keep out of reach of children, etc.) it falls below the 'radar' of FDA and EPA, FOR THE TIME BEING. All this can change. It is not an approved drug for fish, or food fish. But again, for ornamental fish it is basically unregulated as far as the written law is currently concerned.

Q: I have treated with Desa Fin and want to know when I can start treatment with Prazi? Do I have to wait a certain amount of time?? I treated with Desa Fin this past weekend and my fish are still flashing and laying on the bottom. I have tested water and all is in normal ranges...

A: Well, the best thing to do is to RE test your water for everything you can reasonably test for. When you say "All is in normal ranges" it makes me guess that you're fibbing, you tested a couple weeks ago and as far as you could tell, the two tests (Ammonia and Ph) are fine. But there are more critical numbers: Ammonia, Nitrite, Nitrate, PH or Alkalinity. And these numbers change from day to day, so retesting this would be a good idea. Prazi is safe with Desa Fin - however, Desa Fin is not terribly safe, as ALL adehydes are to be treated with respect. You need to figure the formalin content in Desafin and then dose 25-40 ppm total Formalin for 120 minutes and then do a water change. Do the math and you will see why we don't bother carrying DesaFin.

Q: Can Koizyme be used in conjunction with Prazi?

A: KoiZyme is not affected by Prazi, nor is Prazi effectiveness changed by KoiZyme. So they are both safe, and effective dosed together especially since neither one requires a water change.

Q: What is the shelf life of Prazi?

A: Thank you for asking, that's a great question! The jar in my hand, the one I used for that picture on the page, is dated for expiration: FEB 2008 and that's five years off. So, we can assume that any of this product you get from Pondrx can be counted on "for years" and I wouldn't be lying! (Doc Johnson)