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Kill Planaria & Hydra
Kill Planaria & Hydra
Killing Planaria & Hydra with Fenbendazole
Warning: Using chemicals in the aquarium can be harmful to any of the inhabitants. This article should be used as a reference for experimentation and not as a 100% safe method to kill Planaria and Hydra. Please use chemicals at your own risk. Only experienced hobbyists should attempt to use any chemicals in their aquariums. Prevention in the best method against Planaria and Hydra. Also, some species of shrimp may be more sensitive than other species so please use caution.
There are many pests that you can find in an aquarium. However, there are two in particular that annoy shrimp hobbyists the most: Planaria & Hydra. This article pertains to the use of Fenbendazole, an antiparasitic medication, to safely and effectively kill the Planaria and Hydra in your aquarium. For more information of other types of bugs/pests that can exist in the aquarium please read the article What Is That Bug In My Aquarium?
Planaria, also called Flatworms, reach an average size of 0.1 - 0.4 inches (0.3 - 1.0cm). The have two eyes, a triangular head, and come in several different colors the most common being white or pink. They are very slender and have the ability to slither into the tiniest cracks. Their bodies also expand and retract. If they are bothered they will retract their bodies into tiny circles and drop to the substrate. Also, you cannot cut or squish a Planaria as cutting it in fact turns it into two separate Planaria. The only way to remove Planaria is either physically taking them out of the tank with a net or syphon, using shrimp-safe chemicals, or preventing them by not overfeeding.
Planaria are common throughout the Freshwater Aquarium Shrimp Hobby. The main reason is because of overfeeding. When a hobbyist keeps a shrimp only tank, especially for the first time, the mistake of overfeeding can occur. A Hobbyist must remember that shrimp do not eat as much as fish or other types of aquarium inhabitants. You must make sure that you only feed your shrimp what they will consume in 2-3 hours at the most. Once the overfeeding cycle begins the water quality drops, ammonia and nitrate go up, and even worse there is plenty of extra food for pests like Planaria.
Photo of a Planaria
Another one of pests is the Hydra. Hydra are from the Coelenterata family of aquatic invertebrates. Other members of this family include corals, jellyfish, and anemones which are primarily saltwater. One thing to notice is that all of the previously mentioned relatives of the Hydra can also cause harm to other aquatic creatures by methods of stinging, poisoning, etc.
Like its saltwater relatives the Hydra uses its tentacles to capture food. It stings its prey before feeding. It uses its tentacles as pseudo fish lines with barbs to capture small prey, including crustaceans, and feed by bringing the dead prey to its mouth located in in the round portion of the creature. Hydra also feed on tiny food particles floating in the water column. The Hydra is known to feed on small fish fry and some have reported it feeding on small shrimp. Please read the article Are Hydra Harmful to Shrimp? for more detailed information on Hydra. Once again as mentioned above in the Planaria section, it is extremely important not to overfeed.
Photo of a Hydra
Fenbendazole is a medicine used to fight gastrointestinal parasites found in many animals. It is used by farmers, pet owners, aquarists, and many others to fight against parasites in their livestock. Fenbendazole is sold under some commercial names such as Panacur and Safe Guard. For more information on the drug itself please visit the Fenbendazole Wikipedia Page and also its 3dchem Page.
Killing Planaria & Hydra with Fenbendazole
The use of the chemical Fenbendazole has of course been known for a while with various animals. Until recently not much was known about its use with Freshwater Aquarium Shrimp. The thread "Planaria, Hydra and Fenbendazole" in the Planet Inverts Forum is what inspired this article and most information about using Fenbendazole was derived from the various users whom posted in that thread. It has been reported that Fenbendazole can be difficult to dissolve in water and that is may also cause a slight drop in pH. It is important that you do not overdose Fenbendazole as this could cause potential problems. Below you will find successful experience with hobbyist's and their shrimp tanks.
Matt Patrick's Successful Experience
I noticed some Hydra in my Snowball tank after watching a very young Snowball Shrimp fall lifeless to the substrate. There was a berried female on my thermometer who appeared to be releasing newborn shrimp. After a close inspection there were several Hydra on the thermometer and I came to the conclusion the Hydra had killed the newborn Snowball Shrimp. I have no proof since I did not actually see the shrimp being born or watch the Hydra sting the shrimp, it is just a conclusion
As a result of the shrimp death above I decided to try using Fenbendazole to rid my tank of both the Planaria and Hydra. You can buy Fenbendazole at most pet supply stores. It is a dog de-wormer sold under the brand name Safe Guard and was about $14 for four 1 gram packs. According to the package, each gram of the powder contains 222mg of Fenbendazole so 0.1gm would contain 22.2mg. Information on the web is sketchy at best for using this medication with invertebrates.
People describe using a "pinch" of the powder for their tanks or using a "BB" sized measuring spoon for their tanks. Most do not give the gallonage of their tanks so figuring out a dosage from their information is next to impossible. The best info I could find was using a 2ppm dosage to de-worm fish. I was worried about the effects on shrimp with this dosage so I did a little experiment to find the minimum amount required for Planaria and Hydra.
On September 5th I added 0.1gm of Fenbendazole (~.6ppm I believe) to my 10 Gallon Amano/Blue Shrimp tank. This tank had both Planaria and Hydra. The next day, the 6th, the Planaria seemed to be gone but a few Hydra were still hanging on. Later that evening I added another 0.1 grams of Fenbendazole and by the time the lights came on the morning of the 7th, all the Hydra seemed to be shriveled up and dead. The shrimp, snails,and two Rasbora's in this tank are all doing fine.
Also, on the evening of the 6th I added 0.1 grams of Fenbendazole to my 10g Cherry shrimp tank. This tank had Planaria but no apparent Hydra. This dosage seemed to be effective on the Planaria by the next morning. There were no negative effects on adult or baby Cherry Shrimp. Later on one of the berried females in the tank has given birth to more babies. After adding a good amount of food to the Cherry tank the planaria were not visible.
On September 10th I dosed the remainder of my shrimp tanks with 0.1 grams of Fenbendazole. Hopefully, I have found a cure for the Planaria and or Hydra in shrimp tanks. I may need to add another 0.1 grams ( 0.2 grams total ) dose to my Blue Pearl tank since it seems to have a few Hydra on the glass by the gravel. I decided to wait 48 hours (instead of the 24 I waited on the Amano/Blue Shrimp tank) before adding the second dosage to see if a little more time will kill the Hydra.
48 Hours later the 0.6ppm dose of Fenbendazole seemed to have worked for both the Planaria and Hydra in all of my tanks. I can't see any Hydra in my Blue Pearl Shrimp tank.
Two Weeks Later: After two weeks since the original dosing things are going well in all of the tanks. The Planaria and Hydra are still gone and other members have had success with Fenbendazole. Since the initial dosing I have had two more batches of Cherry Shrimp babies and my first batch of Green Shrimp are now swimming around their tank. I will have to wait for my berried Yellows and Snowballs to produce offspring but it looks good at this point. I think my issue has been solved.
Dosing Accuracy: My scale has a readout down to 0.1gm but it also has an accuracy of +/- 0.1 grams. For my dosages, I used a 0.1 grams measuring spoon that comes with one of my LaMotte Test Kits. I tried to calibrate my scale by weighing various amounts of the Fenbendazole. During calibration one level scoop of the powder would not register on the scale. Two level scoops of the powder weighed in at 0.2 grams. Three level scoops weighed in at 0.3 grams and four level scoops weighed 0.4 grams. After removing the initial 0.1 grams dose from the package the remainder of the 1gm package weighed 0.9 grams. While using a "spoon" may not be the most accurate method of measuring a medication for a fish tank it is the best I can do given the accuracy of my scale and seems to be a little more accurate than using a "pinch".
Paul Chapman's Successful Experience
I am based in London, UK, but despite the difficulties we usually have with getting medications I was able to buy some Fenbendazole in the form of a Panacur sachet from vetuk.co.uk. The precise product I purchased was this as it appeared to be relatively pure without additives and also at the amazing price of 43 pence (less than a US dollar). I also ordered different sized syringes that I generally find useful in aquarium keeping and used in this treatment as described below.
My first attempt was in a 10 (US) Gallon Cherry shrimp tank which was infested with Hydra. This tank was filtered with 2 different types of air-powered filters (box and sponge). First I removed the carbon filter to prevent the carbon from elimating the Fenbendazole from the water column. I then took a little less than 10% of the 1g Panacur pack by mixing it in a 20ml syringe with some tankwater. I then began squirting the Fenbendazole mixture in the syringe directly onto any Hydra I could find. The solubility of the powder was limited so I suspect this contributed notably to my success.
After the direct squirting the Hydra rapidly withdrew their tentacles and within a few hours were reduced to little specks or nodules of Hydra flesh curled up on the wood and leaves they were attached to. These nodules slowly vanished over the next 36 hours and my tank is still Hydra-clear despite the lack of any special precautions over two weeks later. I replaced the small amount of carbon in the box filter 72 hours after the initial dose. Total loss of the Red Cherry Shrimp in the tank was zero. They seemed unfazed by the treatment and much happier with the Hydra gone. Not even the little pond snails in the tank were bothered by the treatment.
My second attempt was on a 20 (US) Gallon community tank that houses a few Amano Shrimp, a young Ancistrus, several adult female guppies and a small swarm of White Cloud Mountain Minnows. I was particularly concerned with the Ancistrus so I therefore decided to start with a very low dose and build up slowly.
I proceeded as before, mixing less than 1/10th gram Panacur with tankwater in a 20ml syringe, forgetting to further grind the Panacur into dust as I had determined to do based on the last attempt. I squirted this directly onto the worst-infested areas of the tank. The effects were noticed more slowly and - aware that I was using less than half the initial dose that many had met with only partial success with - considered adding more. I decided to leave the tank overnight and take another look in the morning.
To my surprise and satisfaction, in the morning the Hydra were all in the curled-up nodule state and died/vanished over the next two days without any further dosage. They have yet to return. Note that the 20 Gallon tank is powerfully-filtered with a Fluval 205 external filter and two small internal filters. The canister filters did not seem to inhibit the treatment whatsoever although I did remove the carbon from the 205. Zero casualties were experienced in this tank also. I noticed no downsides to this treatment at all.
My three recommendations based on my experiences are:
1. Given the low solubility of Fenbendazole, use a syringe to target the Hydra directly if possible.
2. Grind the powder to be as fine as possible before use, as my sample at least had a mixture of fine and not so fine granules, which took many days to dissolve.
3. Unless there is some urgency, start with smaller doses (0.05g/10 US Gallons or less) and build up very slowly.
I'll try to answer any further questions if requested. In summary I think this treatment is a wonderful "magic bullet" for Hydra and would recommend it to anyone.
There have been other hobbyists that have also reported success using these methods. Please visit the thread "Planaria, Hydra and Fenbendazole" in the Planet Inverts Forum to post your experience as well as read what other members have said. Feel free to Contact Us as well if you wish to post your experience and information for this article.
Good luck if you wish to try this but please use caution. This type of treatment is more of an experimental type. It is not yet confirmed 100% safe in the long term. I suggest only using this method if you have a serious Planaria or Hydra infestation. Sometimes simply changing the aquarium water and feeding less can reduce or remove a small infestation.