Seahorse Club
Aquarium & Livestock

Feed Ezy Frozen Mysis

Seahorse Club
Aquarium & Livestock

Feed Ezy Frozen Mysis

Seahorse Club
Aquarium & Livestock

Feed Ezy Frozen Mysis

Seahorse Club
Aquarium & Livestock

Feed Ezy Frozen Mysis

Seahorse Club
Aquarium & Livestock

Feed Ezy Frozen Mysis

Seahorse Club
Aquarium & Livestock

Feed Ezy Frozen Mysis

Freshwater dips for Seahorses

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    How effective are freshwater dips for eliminating pathogens in Seahorses? Will these dips also remove parasites? If these dips are recommended, how long should they be and at what temperature?
    Thank you for advise.

    Pete Giwojna

    Dear Fred:

    Freshwater dips will have no effect on pathogenic bacteria or fungal infections, but they are effective in cleansing seahorses and other fish from external parasites, providing they tolerate freshwater dips. Some fish do not. For example, clownfish should never be subjected to a freshwater dip. Most seahorses tolerate freshwater dips very well, but there are exceptions. Hippocampus kelloggi and Hippocampus barbouri seahorses may not tolerate freshwater dips well at all, and I would not recommend dipping those species.

    Scratching and itching are good indications that seahorses are plague by ectoparasites. It is a good idea to provide the seahorses that are scratching with some immediate relief from the parasites by dipping them with freshwater, methylene blue, or even a diluted solution of hydrogen peroxide, or to administer a formalin bath for the itchy ponies. All of these options are discussed in more detail below, Fred:

    Freshwater Dips

    A freshwater water dip is simply immersing your seahorse in pure, detoxified freshwater that’s been preadjusted to the same temp and pH as the water the seahorse is accustomed to, for a period of at least 10 minutes (Giwojna, Dec. 2003). It doesn’t harm them — seahorses typically tolerate freshwater dips exceptionally well and a 10-minute dip should be perfectly safe. Freshwater dips are effective because marine fish tolerate the immersion in freshwater far better than the external parasites they play host to; the change in osmotic pressure kills or incapacitates such microorganisms within 7-8 minutes (Giwojna, Dec. 2003). A minimum dip, if the fish seems to be doing fine, is therefore 8 minutes. Include some sort of hitching post in the dipping container and shoot for the full 10 minutes with your seahorses (Giwojna, Dec. 2003).

    If you will be using tap water for the freshwater dip, be sure to dechlorinate it beforehand. This can be accomplished usually one of the commercial dechlorinators, which typically include sodium thiosulfate and perhaps a chloramine remover as well, or by aerating the tap water for at least 24 hours to dissipate the chlorine (Giwojna, Dec. 2003).

    If you dechlorinate the dip water with a sodium thiosulfate product, be sure to use an airstone to aerate it for at least one hour before administering the dip. This is because the sodium thiosulfate depletes the water of oxygen and the dip water must therefore be oxygenated before its suitable for your seahorse(s).

    Observe the horse closely during the dip. You may see some immediate signs of distress or shock. Sometimes the horse will immediately lie on its side on the bottom. That’s a fairly common reaction — normal and to be expected, rather than a cause for concern, so don’t be alarmed if this happens. Just nudge or tap the seahorse gently gently with your finger if it lies down on its side. Normally, the seahorse will respond to the slight nudge by righting itself again and calm down for the duration of the dip. However, if it does not respond, stop the treatment.

    Most seahorses tolerate the treatment well and experienced no problems, but if you see continued signs of distress — twitching, thrashing around etc. — stop the treatment. (Hippocampus kelloggi end Hippocampus barbouri seahorses may not tolerate freshwater dips and you should consider other treatment options for those species.)

    After you have completed the dip and returned the seahorses to the aquarium, save the dip water and examined it closely for any sign of parasites. The change in osmotic pressure from saltwater to freshwater will cause ectoparasites to lyse (i.e., swell and burst) or drop off their host after 7-10 minutes, and they will be left behind in the dipping water. Protozoan parasites are microscopic and won’t be visible to the naked eye, but some of the other ectoparasites can be clearly seen. For example, monogenetic trematodes will appear as opaque sesame seeds drifting in the water (Giwojna, Aug. 2003) and nematodes may be visible as tiny hairlike worms 1/16-3/16 of an inch long. Other parasites may appear as tiny dots in the water. Freshwater dips can thus often provide affected seahorses with some immediate relief by ridding them of these irritating pests and can also aid their breathing by flushing out gill parasites.

    However, Fred, freshwater dips and formalin baths can be stressful for seahorses that are experiencing respiratory distress and having breathing problems, so if you think the parasites may also be infesting the gills of your seahorses, giving them a quick dip in concentrated methylene blue or deluded hydrogen peroxide may be a better alternative for you.

    Methylene Blue Dip

    For best results, consider administering a very brief (5-10 seconds — no more than 10 seconds maximum) dip in a solution of methylene blue between 30-50 ppm, as described below. Prepare the solution of methylene blue using saltwater from your seahorses tank ahead of time. Time the very short Methylene blue dip closely — maybe keep each seahorse in your hand while you dip it in the blue so there’s no fumbling around to capture it when time’s up — pull the pony out after 10 seconds and immediately return it to the main tank afterwards.

    If you can obtain the Kordon brand of Methylene Blue (available at most well-stocked local fish stores), their suggested treatment protocol for treating external parasites as a dip is as follows:

    For use as a dip for treatment of external parasitic protozoans:

    (a) Prepare a nonmetallic container of sufficient size to contain the fish to be treated by adding water similar to the original aquarium.
    (b) Add 5 teaspoons (24.65 ml) per 3 gallons of water. This produces a concentration of 50 ppm. It is not recommended that the concentration be increased beyond 50 ppm.
    (c) Place fishes to be treated in this solution for no longer than 10 seconds.
    (d) Return fish to original aquarium.

    See the following link for more information on treating with Kordon’s Methylene Blue:

    Click here: KPD-28 Methylene Blue

    If your methylene blue is not Kordon (KPD-28) Methylene Blue, then disregard the instructions above and follow the manufacturer’s instructions for using your brand as a bath or dip instead.

    Another excellent option would be to perform brief dips in hydrogen peroxide as explained below, because they are easier on fishes suffering from respiratory distress and can be administered on a daily basis, if necessary.

    Here are the instructions for performing the very brief hydrogen peroxide dips, Fred:

    <open quote>
    Therapeutic Hydrogen Peroxide (H202) Dips

    A very quick dip 10-second dip in a 3% hydrogen peroxide solution is effective in cleansing fish of Uronema and other protozoan parasites and will also help to disinfect bacterial lesions and promote healing of open wounds and sores. (Note: 3% is the standard concentration of hydrogen peroxide that you obtain at the drugstore or probably have in your medicine chest at home, but this is not the right choice for performing this procedure.)

    Rather, it is customary to obtain the stronger 35% Food Grade or Technical Grade of hydrogen peroxide and then dilute it to the proper concentration instead. For example, 35% hydrogen peroxide was approved for aquaculture use by the FDA in January 2007 and is sold under the name of PEROX-AID(r). This is a much stronger solution of hydrogen peroxide which professional aquarists start with when performing such dips. The desired 3% hydrogen peroxide dipping solution is prepared by taking one gallon of dechlorinated freshwater and then removing 10-oz of the water and replacing it with 10-oz of 35% hydrogen peroxide (PEROX-AID) instead. This formula will produce a ~3% solution of hydrogen peroxide for the brief dip (Kollman, 2003).

    You can also scale this formula down by starting with 1/2 gallon of dechlorinated freshwater for the dip, and then removing 5 ounces of the water and replacing it with 5 ounces of 35% hydrogen peroxide instead. That will again produce a ~3% solution of hydrogen peroxide and 1/2 gallon is enough for dipping seahorses if you put it in a relatively small container rather than a large plastic bucket.

    The 35% Food Grade or Technical Grade hydrogen peroxide can be purchased from chemical supply houses and some online sources, but it is much stronger and more volatile than the drugstore hydrogen peroxide, and must therefore be handled with great care. Be especially careful NOT to confuse the 35% hydrogen peroxide solution with the mild 3% hydrogen peroxide solution from your drugstore when disinfecting wounds or performing the usual first aid measures that the weak solution is customarily used for around the house.

    Once prepared, you can use the same dipping solution for dipping several seahorses in quick succession, but it should then be discarded and you will need to prepare a new solution of 3% hydrogen peroxide each day immediately before you perform the dips, if you will be doing them on a daily basis. This is necessary because the hydrogen peroxide dissipates fairly quickly and must be used immediately after it’s prepared for best results.

    Dip the affected seahorse in the hydrogen peroxide solution for 10 seconds and then return it to the treatment tank. Cup the seahorse in your hand so that you can remove the seahorse quickly after 10 seconds of exposure in the dipping container. The hydrogen peroxide dip will disinfect bacterial lesions and abrasions and help promote healing. The dips have the added benefit of cleansing the fish from some ectoparasites and may help the seahorse’s breathing because the hydrogen peroxide greatly increases the dissolved oxygen levels in the dipping solution. The 3% hydrogen peroxide dips can be repeated once a day or once every three days as needed, depending on the severity of the infection/infestation.

    In summation, the entire seahorse can be submerged in a 3% solution of hydrogen peroxide for a period of 10 seconds to help disinfect wounds or rid them of ectoparasites. DO NOT use a stronger solution of hydrogen peroxide for this procedure! The very brief dips in 3% hydrogen peroxide are a treatment regimen that has been refined by Dr. J. Peter Hill , DVM, who serves as the veterinarian for the Newport Aquarium. He uses it to treat ectoparasites such as Uronema as well as to combat external bacterial infections and to disinfect open wounds or ulcers, thereby helping to promote more rapid healing. He has recommended such baths for seahorses for these purposes…

    In a pinch, some hobbyists will use the 3% hydrogen peroxide from their drugstore, but for best results, it’s safer to start with a concentrated 35% Food Grade or Technical Grade, or better yet the 35% PEROX-AID designed for use in aquaculture, and then to dilute it to 3% H2O2 as previously described.
    <Close quote>

    Another alternative would be to use formalin treatments at 1ml/gal for a 1 hour bath every other day until the scratching stops for up to 3 treatments. However, unlike hydrogen peroxide which increases the level of dissolved oxygen in the dipping container, formalin consumes oxygen and can therefore be hard on seahorses that are having breathing problems of any type, so bear that in mind. The formalin does have the added virtue of working wonders with seahorses when they’re cloudy eyes are due to monogenetic trematodes or eye flukes, and formalin is helpful in treating some pathogens such as fungus or certain skin infections. If you try the formalin baths, Fred, be sure to observe the precautions outlined below:

    Formalin Baths

    Many commercial formalin products are readily available to hobbyists, such as Kordon’s Formalin 3, Formalin-F sold by Natchez Animal Supply, and Paracide-F, sold by Argent Chemical Laboratories. Or whatever brand of formalin is available at your fish store should work fine.

    A formalin bath simply involves immersing the seahorse in a container of saltwater which contains the proper dosage of formalin for a period of 60 minutes before returning it to the main tank. Include a hitching post of some sort in the container and follow these instructions: place the fish in a three-gallon bucket or a similar clean, inert container containing precisely one gallon of siphoned, aerated tank water. Medicate the bucket of water with with the appropriate amount of formalin for a concentrated bath according to the directions on the label. Place an airstone in the bucket and leave the fish in the bath for up to 60 minutes. If at any time the fish becomes listless, exhausted or loses its balance, immediately place the fish in clean, untreated water in your hospital tank.

    I want you to be aware of these precautions when administering the formalin bath:
    Formalin has limited shelf life and degrades to the highly toxic substance paraformaldehyde (identified as a white precipitate on the bottom of the solution); avoid using any formalin product which has such a precipitate at the bottom of the bottle.
    Formalin basically consumes oxygen so vigorous aeration must be provided during treatment.
    Time the bath closely and never exceed one hour of chemical exposure at this concentration.
    Observe the seahorse closely during the bath at all times, and it show signs of distress before the allotted time has elapsed, remove it from the treatment immediately.

    If you can obtain Formalin 3 from Kordon at your LFS, Fred, these of the instructions you should follow for your formalin dip:


    (a) To a clean, non-metallic container (i.e., a plastic bucket), add one or more gallons of fresh tap water treated with Kordon’s AmQuel . For marine fish use freshly prepared saltwater adjusted to the same specific gravity (or salinity) as in the original tank. Make sure the temperature in the container is identical to that in the aquarium
    (b) Add 1 teaspoons of Formalin·3. This produces a concentration of 100 ppm. formaldehyde.
    (c) Agitate the solution with an airstone and adjust for a moderately strong flow of air.
    (d) Remove the fishes to be treated and deposit them in the container for a treatment period of not more than 50 minutes. Immediately after the treatment period, or if signs of distress are noted, remove the fishes to a previously prepared recovery tank. The fishes may be returned to their original tank, but the presence of the original disease-causing agents in the tank water may result in a reoccurrence of the disease condition.
    (e) Observe recovering fishes. Make sure that tankmates do not molest them during recovery.
    (f) Repeat treatment as needed, every week. Each treatment is very stressful to the treated fishes. Do not reuse the dip solution.

    For additional information on treating fishes with Formalin 3 by Kordon, see the following web page:

    Click here: KPD-54 Formalin-3

    If you get another brand of formalin, just follow the instructions that it comes with for a concentrated bath or dip (not prolonged immersion or a long-term bath).

    Any of the dips are baths mentioned above should provide your itchy seahorses with immediate relief, Fred. However, for a heavy infestation, it is also necessary to treat the seahorse tank in order to eradicate the parasites. There are run number of treatment options that would accomplish that goal.

    For instance, the seahorse tank could be treated with chelated copper sulfate, Paracide-D, Parinox, or Osmotic Shock Therapy (i.e., hyposalinity) after removing sensitive invertebrates. Let me know if you want to try the hyposalinity, Fred, and I will provide you with detailed instructions for administering it safely.

    Pete Giwojna


    Hi Pete,

    i have a question about fresh water dipping H. reidii, will it be ok for the specie to have a schedule prophylactic fresh water dipping?, how often can it be done?

    thank you,


    Pete Giwojna

    Dear Allan:

    Yes, sir, Hippocampus reidi seahorses will typically tolerate a freshwater dip very well. They are not especially sensitive and normally do not have any problems with such a procedure.

    However, Allan, you must always be aware that being subjected to a freshwater dip is inherently stressful for a seahorse. Dipping requires the seahorse to be handled, removed from the main tank and its tankmates, and then subjected to unnatural conditions for several minutes. Although most of our amazing aquatic equines tolerate the procedure pretty well, it’s never a good idea to subject the ponies to repeated freshwater dips or to administer freshwater dips on a regular basis prophylactically…

    If you notice scratching or itching or any other indications of a problem with external parasites, a freshwater dip can be a useful first aid measure that can provide your seahorses with some quick relief. But dipping is not a solution to a problem with ectoparasites, since it will cleanse the seahorse of any such parasites it may be carrying, but the pony will be quickly reinfested once it is returned to the main tank if there has been an outbreak of external parasites in the aquarium…

    So if the seahorses are displaying symptoms of a parasitic infestation, you might perform a freshwater dip once as a first aid measure to provide them with a little relief and buy you time to go to your local fish store and obtain a good medication that you can treat the main tank with, Allan, but you don’t want to be administering freshwater dips to the ponies daily or anything like that in order to try to control such a problem.

    Rather, it’s best to treat the main tank with a good antiparasitic that will not have an adverse effect on the biological filtration, such as metronidazole or praziquantel, or a medication that includes both metronidazole and praziquantel, such as General Cure by Aquarium Pharmaceuticals:

    General Cure by Aquarium Pharmaceuticals

    * Anti-parasitic fish medication rapidly treats a wide variety of parasitic diseases
    * Effective fish medication for use in fresh and saltwater aquariums
    * Treats diseases such as gill & skin flukes, hole-in-the-head disease, anchor worm, velvet, and fish lice.

    Easy-to-use fish medication contains metronidazole and praziquantel in quick-dissolve powder form. Treats a wide variety of parasitic diseases – including velvet, anchor worm, fish lice, hole-in-the-head disease, and gill and skin flukes. Will not color water. For use in both freshwater and saltwater aquariums. Each packet doses 10 gallons. Economical 850 gram bulk jar doses up to 3,270 gallons and includes a 1 tsp scoop.
    Active Ingredients: 250 mg Metronidazole and 75 mg Praziquantel per packet.
    Directions for Use: For best results, remove activated carbon or filter cartridge from filter and continue aeration. For each 10 gallons (38 L) of water, empty one packet directly into aquarium. Repeat dose after 48 hours. Wait another 48 hours then change 25% of the aquarium water and add fresh activated carbon or replace filter cartridge.
    This package treats up to 100 gallons. Two doses required for full course of treatment.

    Diagnostic Chart
    Gill & Skin Flukes: Very common fish parasites. Can be found on the gills, scales or skin. Not visible without the aid of magnification. Symptoms may include: darkening of skin, clamped fins, excess mucous. Fish may also swim erratically or become emaciated.
    Hole-in-the-Head Disease: Symptoms include pitting and erosion of skin and muscle tissue around the face and side of body. Many infected fish exhibit poor appetite, weight loss and nervousness
    Anchor Worm: These worms penetrate the skin and embed an anchor-like attachment into the fish. Often a thread-like appendage is all that is visible. Fish tissue is often red at the point of attachment. May be difficult to see without magnification.
    Velvet: Heavy infestations cause a golden, velvety appearance or small, white spots on the sides of fish. Gill infestation may cause labored breathing and scratching on objects in the aquarium.
    Fish Lice: A parasitic crustacean that can easily hide under the scales or other parts of fish. Fish lice pierce the skin, sucking blood and tissue fluids. Magnification is typically required to see fish lice.
    Another good option for a persistent problem with external parasites would be to administer hyposalinity in the main tank for a period of several weeks.

    Please let me know if you’re ever having the problems with a parasitic infestation in your main tank, and I can provide you with detailed instructions for administering the metronidazole and/or praziquantel safely, or for treating the main tank with hyposalinity, Allan.

    Best wishes with all your fishes, sir!

    Pete Giwojna, Ocean Rider Tech Support

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