Category: Medication Reviews

Treating Bacterial Diseases with Seachem Kanaplex & Metroplex

When dealing with bacterial diseases, Seachem makes two of the most effective medications on the market. Kanaplex and Metroplex are both powdered antibiotics which should be your go-to medications when you think your fish has a bacterial disease such as columaris, tuberculosis, popeye, fin rot, dropsy, etc. It’s easy to use, highly effective and in my opinion safer than alternatives like API Furan-2. I’ve found that Furan-2 kills off beneficial bacteria quicker than Seachem’s products and Furan-2 can be easily overdosed. Kanaplex and Metroplex are also more versatile in the respect that it can be fed directly to your fish so you don’t have to treat an entire tank if you don’t want to.

Because many people misdiagnose their fish I strongly recommend using Kanaplex and Metroplex in combination with another when treating for a suspected bacterial infection. This is not only safe but in my experiences have made the medications more effective.

For some cases of stubborn infections, like columnaris, you must combine these two medications because it’s the only way in-which they are effective which is also a reason that I recommend using both. More on this later.

While they both look like similar products they each excel in different areas which we will get into a bit later. The benefit to using them both is to cover all sorts of different bacterial diseases because some strains of bacteria may not respond to one medication or the other.

Things to Consider:

While it’s always a good idea to supplement your beneficial bacteria bed when treating with antibiotics I haven’t observed any noticeable impact on my tank’s cycle when using either of these products. However, if you overdose them, which I do not officially recommend there is the chance you start a mini-cycle. Personally, I have overdosed the medications intentionally under close observation with no adverse side effects but please do so at your own risk.

Continued usage of these medications can lead to kidney failure, so I advise giving your fish at least three days to rest before repeating the treatment if possible. This means that if you administer them for the recommended three doses, 48 hours in-between doses, and you wish to do another round of treatment you should consider waiting three days before doing the second round. You do not have to do this, but if your fish will be okay without the medication it’s a good way to ensure your fish stays healthy in the long run.

Water changes aren’t necessary while medicating because after 48 hours these medications are no longer active in the water column and thus can’t build up to toxic levels.

You should remove all forms of chemical filtration when using either Kanaplex or Metroplex. This includes but is not limited to: carbon, Seachem Purigen, Poly Filter, Chemi-Pure Blue/Elite.

Seachem recommends that you remove invertebrates from the tank you’re treating, I haven’t done this and haven’t had any deaths due to the medication. However, if you plan to treat an entire tank then I would advise you listen to the company who makes the product and remove your inverts.

Seachem Kanaplex:

Kanaplex is a blended kanamycin based medication which is very effective against gram negative bacterial diseases as well as some fungal infections. Kanaplex can be added directly to the water column or mixed with food to treat only a specific fish. A big advantage of Kanaplex is because the fish absorbs the medication through it’s gills and skin it’s useful in treating internal infections even when the fish is refusing food.

Kanaplex is especially effective treating columnaris, dropsy, fin rot, pop eye and even fish tuberulosis.

Use 1 level measure (included) to every 20 L (5 gallons). Repeat every 2 days until symptoms disappear or up to a maximum of 3 doses. Turn off UV, ozone, and chemical filtration. To feed, blend 1 measure with about 1 tablespoon of frozen food paste. To minimize loss during feeding use with Focus™. To enhance palatability use with Garlic Guard or Entice. Food may be refrozen.

Active ingredients: kanamycin sulfate (32%)


Seachem Metroplex:

Metroplex treats for many protozoan and anaerobic bacterial diseases. Anaerobic bacteria is far less common however, some stubborn infections like columnaris rarely respond to Metroplex or Kanaplex by itself, however it will usually respond when these two medications are combined. It’s not fully understood why this is but Metroplex and Kanaplex form a symbiotic bond making the medications much more effective.

Use 1-2 level measures (included) to every 40 L (10 gallons). Repeat every 2 days until symptoms disappear or up to a maximum of 3 doses. Turn off UV, ozone, and chemical filtration. To feed, blend 1 measure with about 1 tablespoon of frozen food paste. To minimize loss during feeding use with Focus™. To enhance palatability use with Garlic Guard or Entice. Food may be refrozen.

Active ingredients: metronidozole (70%)

If you have any questions about either of these medications or an entirely different medication feel free to message me on Facebook! I’m more than happy to give you personal advise and/or diagnose your fish for you.

Seachem Paraguard – A Cure-All?

There is no such thing as a cure-all, but Seachem Paraguard is as close as you’re going to get. Many people’s recommendation to treat fish involves salt regardless of the illness and thus it has this reputation of being a must-have medication for your aquarium but in reality, the must-have medication is Paraguard.

Salt can be harmful to fish like corydoras catfish or plecos and many plants don’t tolerate salt well at all. Salt is also not nearly effective enough, in my opinion, to warrant the side-effects. I view it as an old-fashioned method of treatment and because a lot of local fish stores are being run by an older generation they often pass along their perception of salt treatments and thus the cycle of misinformation continues.


About Seachem Paraguard: 

According to Seachem, Paraguard uses a “proprietary, synergistic blend of aldehydes, malachite green and fish protective polymers that effectively and efficiently eradicates many ectoparasites (ich, etc.) as well as external fungal/bacterial/viral lesions like fin rot.” Seachem doesn’t market Paraguard as being plant and invertebrate safe because they say it would be impossible to test it with every single plant and invert under any possible water parameters. However, from personal experience I can attest to the fact that Paraguard is an extremely safe medication that can be used in planted aquariums, aquariums with scaleless fish like corydoras catfish and aquariums with inverts such as snails.

Paraguard is also safe in the sense it won’t harm your beneficial bacteria bed, causing your tank to crash and in all likelihood it won’t stain your silicone and/or decor. There is the chance of minimal stains as there is malachite green in the medication but I’ve never heard of it causing any sort of stains. I have also personally used it many times and never have I encountered any issues with it staining or even tinting the water a different color. It does come out of the bottle a very deep blue, but it has no noticeable effect on the color of the tank water after a few seconds of it entering the aquarium.

Why is it a Must Have?

Seachem Paraguard is a must-have medication in your cabinet for numerous reasons, I like the fact that it’s a very safe medication which is well-tolerated by all types of fish. Personally, I’ve used it with scaleless fish like Figure Eight Puffers and corydoras catfish, I’ve used it with Nertie Snails and Red Cherry Shrimp and a number of community fish like German Blue Rams, Tetras and Guppies. Another big reason I use it is because of it’s versatility.

If you aren’t exactly sure what is wrong with your fish then Paraguard is always a good choice, not only is it safe and effective but it treats such a wide-range of illnesses that you can successfully treat many different diseases without a proper diagnosis. It’s versatility also comes in handy when you’re dealing with multiple diseases at the same time and it also helps prevent secondary infections that take hold when a fish’s immune system is already comprised by an illness.

Personally, I have successfully treated ich, fin rot and fungal infections with Paraguard. I also dip all incoming plants in it overnight to greatly reduce the risk of ich outbreaks in my main tanks.

Dosing Directions:

Paraguard is a very easy medication to dose, however the dosing directions provided below (from Seachem’s website) should be followed to ensure safety and effectiveness.

 “In the aquarium, use 5 mL (1 capful) to every 40 L (10 gallons*). Repeat daily as required as long as fish show no stress. For 1 hour dips, use 3 mL per 4 L (1 gallon*). Dips may be extended if fish show no evidence of stress.”

Water changes during treatment aren’t necessary as after 24 hours, Paraguard is no longer active and will not build up to toxic levels. This also means that you must repeat the dose daily if you wish to achieve maximum effectiveness. If water changes are required for any other reason, you should change the water and then do that day’s dosage of Paraguard immediately after the water change to ensure you’re maintaining a therapeutic dosage in the water column.

If you have any other questions about Seachem Paraguard, feel free to message me on our Facebook page and I will be sure to get back to you as soon as I possibly can!