Walk into your local fish store and ask for something to use as a coral dip and more than likely Praziquantel (Prazi for short), wont be the first thing that is recommended to you. Products like Coral Rx, etc etc have garnered much of the coral dipping buzz in recent years and non aquarium products like Bayer complete are widely used as well. Prazi has been around for many years in the fish industry, used mainly as a treatment for parasites on marine and freshwater fish, but it is also a very effective coral dip.
Prazi can be used in both fresh and saltwater and has been used for many years to treat parasites, tapeworms, flatworms, and flukes in fish. It is often dosed right into tank water when used to treat fish, though we always use it in a quarantine tank or dip bucket when treating corals so we don’t kill any of the animals in our main tank that would also be killed along with things like flatworms and nudibranchs . It seems to be one of the more gentle ways to kill parasites on corals as we have done some dips well over an hour without any visible signs of stress to the corals whatsoever.
How we use Prazi?
The dosage for treating fish is 5ml per 10 gallons of tank water, but for corals, we have safely dipped using that same 5ml per 1 gallon of saltwater. Again, we do this outside our reef tanks in a QT or dip bucket. It is important to note that since you can extend these dips well past the normal 5-10 minutes, adding a heater to your dip is a great step to keep the temperature as even and similar to your tank as possible.
Our team discovered Prazi’s effectiveness on certain marine pests by accident only a year ago. We were dipping some monti rocks that came in from an aquaculture facility and noticed hundreds of monti eating nudibranchs and their eggs covering the rocks right at the coral/rock line. We decided to separate a few of these rocks and test out a few treatments. We used Bayer on one group, prazi on another and coral Rx on a third. The corals were dipped for 10-15 min and then placed in our QT tanks. Making a long story short, they all killed the adults, but to our surprise, the Prazi seemed to also kill the eggs. We saw that a few weeks after the dip, the colonies that were dipped in Rx had new small adults on them, while the Prazi and the Bayer did not and the Prazi seemed like a much less toxic thing to be using in and around our tanks. Someday time permitting, it would be interesting to run a true experiment in separated tanks and with a single pest to gauge its effective concentration etc.
Another thing we use prazi for is to erradicate the annoying planaria flatworms ( these are the ones that don’t eat coral, but just look like hell in your tank ). We like to suck out as many as we can using a hose in our main display that siphons down into a filter sock in our sump. This way you aren’t losing water and you have an easy way to catch and remove as many planaria as possible before treatment. **PLANARIA CONTAIN TOXIN AND CAN KILL YOUR ENTIRE TANK IF YOU DOSE WITH TOO MANY OF THEM LEFT IN YOUR SYSTEM** There now that you have seen the disclaimer, treat your tanks at will once you have removed literally every planaria you can see. It will take the population down to near 0 and your six line and other wrasses can keep the population low from there. Again, be very careful in dosing into your entire system for planaria. do a 25% water change right after and use carbon to take out the toxin these little things release upon dying.
In addition to the success we saw treating monti nudibranchs and flatworms ( AEFW and Planaria), Prazi also has the benefit of longer dip times way way past the 10 or so minutes other treatments recommend. At the prescribed concentrations, we usually leave new corals in over an hour now with 0 negative effects on the corals observed at all. As with all treatments, we do like to do a couple of dips over a few weeks before we clear our corals for sale or placement in our main systems.
As with all of our featured products, Prazi is currently on sale here.