# Killing hydras?



## Zapins (Jul 28, 2004)

What is the best way to kill hydras only? I spotted a few in my pygmy sunfish tank. They are spawning a lot so I am feeding them baby brine shrimp daily which the hydras are eating. Are there chemicals I can add to kill only the hydras but not any of the babies or infusoria they eat?


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## joshvito (Apr 6, 2009)

I would also like to know this. Every time I am feeding BBS, I get hydras all over. I manually remove as many as possible, but they multiply quick. With larger fry, they don't bother me so much. However, I currently have smaller killie fry, and I worry that the hydra may get the fry too.


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## mythin (Sep 2, 2007)

I used fenbendozole in a pure line CRS tank, no losses of shrimp or snails, shrimp even ate a little bit of the white powder that wasn't broken down, still they are fine. All my hydra shriveled and died within 24 hours. If its a particularly bad outbreak you may need to do it twice.

This is what I used: http://www.amazon.com/Safe-Guard-Canine-DeWormer-Small-1-Gram/dp/B000FPH2EW/ref=pd_sim_petsupplies_2

dosage: 1/10th of 1 gram per 10G of water.

I separated out the 1gram packet into 10 equal parts, (eyeballed it), used 1/10th and tried to crush it up into the finest powder I could (its not very water soluble, but you can crush it as much as you can to help).

Took the 1/10th powder mixed and in another container mixed it with some of the tank water. Used a syringe to suck up all the powder/tank water, and then spot treated directly onto the hydra, they will shrink immediately, and in about a day shrivel and fall off. I recommend doing it with the lights off as light will break down the fenbendozole faster. Wait 24 hours, do a 20-30% water change, if hydra remain, do a second treatment 2-3 days later.

I have heard it might kill nerites, but it did not affect my pond snails or ramhorns. Does not affect fish or shrimp.


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## Zapins (Jul 28, 2004)

I read up about fenben and it seems like its pretty good stuff, non toxic to nearly everything else and very low side effects. I was reading a study on overdosing it with sensitive freshwater fish like bluegills. Basically the gist of the paper was it becomes mildly toxic after being around for 10 days in the water at saturation levels (where it can't dissolve any more into the water). But it is broken down quickly by light and soil which binds and sequesters it so it appears to be hard to build it up to toxic levels unless you are dosing every day. Additionally, it has absolutely no detectable effects on plants at saturation doses no matter the length of time it is dosed.


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## gundaman (Feb 24, 2013)

try using panacur, I heard it works for hydra's. I just bought some and and will be dosing in my tanks, I will let you know how it goes, thanks.


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## Zapins (Jul 28, 2004)

Panacur = fenbendazole. Panacur is the brand name, fenbendazole the chemical name.

Let us know.


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## BruceF (Aug 5, 2011)

Guppies seem to work!


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## niko (Jan 28, 2004)

I think a sword is the traditional weapon.









However, you may need a smal one (depending ot the size of your tank).


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## Zapins (Jul 28, 2004)

Haha niko that's great 

I'll have a look and see if I can find some smaller swords.

Here are some quotes from the study I read at http://www.fda.gov/downloads/Animal...rocess/EnvironmentalAssessments/UCM078335.pdf

Solubility:


> The saturation point of fenbendazole in water (0.01 mg/L), in other words it is soluble in water only at a maximum level of 10-40 micrograms/L.


Toxicity vs. fish


> Toxicity was found when bluegill were exposed for more than 10 days to concentrations of more than 12-1 9 micrograms fenbendazole/L.


Toxicity vs. water flea:


> The 48 hour LCso for the water flea exposed to fenbendazole was estimated to be 12 micrograms/L (1 1-14 micrograms/L).


Toxicity vs. bacteria:


> The highest tested concentration of fenbendazole was 100 micrograms/mL agar. No antibacterial effect could be found against any of the tested anaerobic bacteria.


Toxicity vs. protozoa:


> Fenbendazole was tested against these protozoa in in-vivo experiments: No activity was found in any of the experiments.


Toxicity vs. fungus:


> An antifungal test was also performed against:
> No inhibition of fungi was observed in this study


Fenbendatole Breakdown:


> It would be expected that the amount of fenbendazole released into water run-off would be very much lower than 496 ppb because fenbendazole is very insoluble in water, absorbs tightly to soil particles and is rapidly photodegraded. Therefore, fenbendatole is not expected to migrate from application sites into runoff or leachate water; and hence, is not expected to be toxic to aquatic species. Also, fenbendazole will be present at very low levels in the soil, and it is soluble in water only at a maximum level of 10-40 rnicrograrns/L.


Bio accumulation of fenbenazole:


> These data indicate that fenbendazole would not be expected to concentrate or be retained to any great degree by aquatic organisms. From all of the available information we conclude that fenbendazole should not pose a significant problem concerning bioaccumulation


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## ryantube (Aug 9, 2011)

Just go with fenbendazole. I wrote an article about it. Safe and effective.
http://www.aquadic.com/2012/03/using-fenbendazole-to-kill-hydra-and.html


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