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Efficient Hydra Removal

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  • Efficient Hydra Removal

    Hey everyone, wasn't sure which board was the right one, so it's going here. I haven't seen this method mentioned for treatment, so I figured it was worth noting for the future.

    I recently had a hydra outbreak; one tank I hadn't been watching too closely ended up with hundreds of them inside of a few days. A daily dose of 8-8.5ml/L of excel over the past 3 days has brought them down to perhaps 1-2% of their original polulation. The existing hydrazoa seem to be rather slugish, and I don't expect them to last much longer.

    This method is preferable to most other treatments as it has little effect on fish, plants and even most inverts at this level of dosage. Should I end up with another infestation, I may try it at a half dose for the sake of those keeping more sensitive species of plants.

    Last edited by Philosophos; 08-06-2009, 12:37 AM.
    - Dan

  • #2
    Hi.. maybe this is too late.. years ago I have used Gouramies to eat them, they are very efficient at it.
    Luis E.


    • #3
      Not too late at all. I ended up with a little contamination going on, and noticed that the hydras didn't make it too long in my apisto tanks. It was the bristlenose spawning tank that had the issue, and it took a while to get rid of them completely. As an update, I'll say that they seemed to rebound after a week or two if excel dosing wasn't constant; it ended up taking a while to stomp them out completely.
      - Dan


      • #4
        Asolene Spixi

        This guy reports that Asolene Spixi (zebra apple snail) eats them. I have had no experience with either hydra or this snail.


        • #5
          Anything small and carnivorous seems to eat them as well. I noticed that dropping in a pair of apistos clears out a tank at an incredible rate.
          - Dan


          • #6
            My problem is that the hydras are in with the cherry shrimp so putting in apistos would probably clean everything out.



            • #7
              Originally posted by shoggoth43 View Post
              My problem is that the hydras are in with the cherry shrimp so putting in apistos would probably clean everything out.

              I second what ghostsword said above about gouramis, four of the sparkling variety destroyed my hydra issue. What about neon tetras, or endlers if you need something smaller?


              • #8
                Apistos are hit and miss with shrimp. I've heard of some success, but I've also lost a number of shrimp. One spawning female is all it takes to never see your shrimp in the open for that matter.

                I wonder if any number of smaller characins would do the job as well. The only tanks I've had them hang around in are ones filled with herbivores.
                - Dan


                • #9
                  PP In The Aquarium

                  Hi S, All,

                  If you must rid yourself of freshwater hydrozoans, you can:
                  1. Pull everything out of the tank and sterilize it with Chlorine bleach
                  2. “Vienna” method, remove the plants and critters and raise the water temperature above 108 F (42 C) for a couple of days and do a good Potassium permanganate or bleach dip with the plants.
                  3. Flubenol (flubendazole) is also very effective against hydra used at 1-2 mg/l; I think Albendazole is the new version.
                  4. Potassium permanganate (KMnO4) at 2mg/l that is about 0.9 gram for a 120-gallon tank for four hours
                  5. Biological control, all the aforementioned are good, then of course you need to culture hydras to continue feeding the biological control critters. Also just about anything that eats Hydras, will if large enough, eat the shrimp.

                  Freshwater hydrozoans are kind of a big non-issue; most tanks have a lot of other life in them, the hydras are simply large enough for us to see. Hydras can and are a danger to fry, then so are any of the biological control critters you might introduce.

                  I have heard of and seen one instance where hydras may have harmed a mature Otocinclus affinis. The situation I witnessed was a poorly maintained tank, with water conditions I would have been amazed to see Ottos surviving.

                  The Potassium permanganate (KMnO4) treatment is explained at I have found the Potassium permanganate treatments at these levels safe for my critters down to shrimp; it will harm populations of smaller invertebrates, but then that is the idea in this case.

                  I recommend that you experiment first with a couple of your critters prior to treatment in the main tank. If you have never done this before be extra vigilant, err on the low side in concentrations. Should you notice any adverse reaction or just find yourself pooping uncontrollably, add whatever de-chlorinator you use at the proscribed rate.

                  One of the reasons I like the Potassium permanganate method is that it is also a good indicator of water quality. Take my 80-USgallon tank.
                  We need 2mg/l of PP so:
                  Grams of PP=80-gallon*0.0038*2mg/l=0.6-g PP
                  (if you have a scale accurate enough and are using technical grade Potassium permanganate, feel free to measure out 0.61 or 0.608 g of PP).

                  Dissolve the PP into a liter of aquarium water, and then pour the solution along the length into the aquarium. Note the time or set an alarm for four hours.
                  The aquarium water should turn a pleasant pink or even light purple (were it not for the profanity laced replies from the Plant Guru Team, I would tell you the approximate ORP values the different colors tend to represent).
                  Light purple means your water quality is excellent and you can even use a little less PP the next time. Pink is also an indicator of good water quality and that the dosing is correct. Yellowish tint through mud brown indicates poor water quality and the quicker and darker it got the worse the water quality.
                  If your aquarium got into the yellow to dark browns in less than four hours, add another 2mg/l dose that is another 0.6 grams of PP. Continue the process until you make it four hours in the pink. The color may, in fact should fade, to pretty much invisible, if not add some de-chlorinator to the water.

                  Most discover that excellent water quality tends to preclude many of the critter problems.

                  Back in the day as the Earth cooled, before the knowledge of water changes this is the way we removed the organics from the water. :gw Many pond keepers even unto this day use this process since major water changes may be prohibitive or even impossible.

                  The first sign we don't know what we are doing is an obsession with numbers. - Johann Wolfgang von Goethe

                  Disclaimer: I am not trying to make you mad, it is just what I am, an evil plant monster, 'nuf said.
                  • I believe the information I am giving is sound, I am not a veterinarian, professional chemist or particularly bright and certainly not a "Guru.".
                  • I assume you are of legal age, competent and it is legal for you to acquire, possess and use any materials or perform any action in your in your jurisdiction.
                  • When in doubt "don't."


                  • #10
                    In this case I ended up with other problems. Namely the LED falling into the tank fiasco so I think the hydra/limpet problem in this tank is now sadly a nonissue. This will likely be broken down and stored for a bit until I can get things settled and going again.