aquarium and pond answers, information, articles, resources

Freshwater, Marine, Sick Fish, Lighting, Baths

Our Facebook Page to Follow: Aquarium/Pond Answers Facebook     DONATE

This is a unique resource for answers, help, & advice to aquarium and pond questions not found elsewhere; With regular posts & article updates.

In our research; we use aquaculture, horticulture, medical, & university research to compile many of our articles.

  See our AQUARIUM ANSWERS DIRECTORY page for topics by category.  

Our Recommended Lighting for highest efficiency professional planted/reef aquariums: "AquaRay Lighting"

Neon Tetra & FNT Disease; Sporozoan Fish Infection

NEON TETRA DISEASE (Identification, prevention and possible treatment of):
Also the similar infection; FNT Disease (False Neon Tetra Disease)

(Scroll further into the article for FNT)

By Carl Strohmeyer-PAMR 40+ years experience
Updated 2/4/21

Neon Tetra Disease, Pleistophora hyphessobryconis
This term is often a catch all name for diseases of Neon Tetras specifically and many other fish as well, especially other Tetras.
The usual cause is by a Sporozoan (parasitic spore-forming protozoan which reproduce sexually and asexually in alternate generations by means of spores); Pleistophora hyphessobryconis, although there are other causes including many fungi that will imitate this Sporozoan infection.

The true Pleistophora hyphessobryconis infestation is very difficult to treat, and basically impossible to treat in the later stages of this infestation, which is when most aquarists first notice this disease.
However, contrary to popular opinion on the web and elsewhere where many are just repeating what they hear/read elsewhere it is SOMEWHAT treatable in the early stages and VERY preventable from spreading based on my long time professional experience and experimentation.

Occasionally rare gram positive bacteria will also cause these symptoms (fading, loss of color, etc.) which require a different course of action.


The disease cycle begins when parasitic spores enter the fish after the fish ingests infected food or organic debris, such as the bodies of dead fish, or live food (often Tubiflex Worms).
After the spores enter the intestinal tract, the newly hatched embryos burrow through the intestinal wall and produce cysts within the muscle tissue. These muscles containing the cysts begin to die, resulting in a pale whitish tissue.

Initially the only symptom may be restlessness especially when lights are turned on and off.
The infected fish often will stop schooling with others of their species. Soon the swimming becomes more erratic and the tell tale symptom of the white muscle tissue becomes apparent.

Other fish are susceptible to this infestation as well, this includes and is not limited too:
*Most Tetras
*Many Danios (including White Clouds)
*Angelfish & other Cichlids

Symptoms in order of progression:


Before any aquarium/pond fish treatment it is important to know all the steps as often treatment is much more than dumping medication into an aquarium.
Please read this article before ANY aquarium treatment regimen:
Fish Diseases | How to Treat Sick Fish

TREATMENT (and more importantly; stopping the spread of this disease):

Removal of ALL infected fish from main aquarium if at all possible (along with the use of true UV Sterilization in the main aquarium).

A "bath" with Methylene Blue is the first step.
To prepare this bath I use 1-2 teaspoon 2.303% solution per 5 gallons in a bath of aquarium water from the tank the fish you wish to treat came from, I usually use about a ½ gallon of water, however you may use less. With Kordon's Methylene Blue, 10-20 drops per gallon will work.

Measurement of the Methylene Blue does not need to be too precise as this bath should only be used for about 30 minutes and Methylene Blue is safely overdosed for fish in baths, dips, or bare hospital tank. However overdosing in established aquariums can kill beneficial nitrifying bacteria.

This bath’s effectiveness is improved further by the addition of salt (at 1 teaspoon per gallon) AND Metronidazole at double the normal "in-tank" dose recommended by the manufacturer.

A Medicated Bath Resource:
How to Perform a Medicated Bath
Recommended Product Resources:
*AAP MethyBlu (Premium Methylene Blue formulation)
*AAP/SeaChem Metronidazole (Metroplex)

Make sure you keep the water in a warm area, as in a cold room the water temperature can drop rapidly which would stress the fish.
Do NOT pour this water back into your display aquarium when finished.
This bath can be performed twice per day.

Adding Nitrofurazone to this bath at double recommended tank dose can improve results.
Erythromycin can be substituted, especially for FNT Disease (Erythromycin Phosphate as found in AAP Mycin is more effective than the Erythromycin Sulfate found in API Erythromycin or Mardel Maracyn).
This bath is helpful for the both “True Neon Tetra Disease” and false neon tetra disease (FNT Disease).

In tank; I suggest the use of Naladixic Acid for just one dose, followed in 24 hours by a water change. If not all fish are affected, I suggest a hospital tank for this, although often Neon Tetra Disease picks off fish one by one some display aquarium treatment becomes necessary.
Naladixic Acid (at double tank dose) can also be used in lieu of Nitrofurazone (Pharmaceutical grade AAP Furacyn or less effective Furan 2) in a bath combined with Methylene Blue.

Product Resource: AAP Naladin; Naladixic Acid

Alternative "in tank" treatments (but less effective than Naladixic acid) includes ParaGuard-Parasite or Super Ich Plus (Super Ich is stronger than ParaGuard) combined with either Nitrofurazone (AAP Furacyn or less effective Furan 2) or Metronidazole.
Another alternative is the use of AAP Myacin in the main aquarium, although this is more effective for FNT Disease (discussed later), or simply for unknown Tetra "die offs".
Medicated Wonder Shells are excellent as a follow up treatment or for mild infections.
Continue this treatment for 7-10 days.

Recommended Product References:
*AAP Myacin (SUPERIOR Erythromycin Phosphate)
*API Erythromycin
*AAP ParaGuard-Parasite Treatment
*AAP Super Ich Plus
*AAP Furan 2
* For a good follow up treatment either after fish have mostly recovered or as a preventative:
AAP Medicated Wonder Shells

AAP Fish MerbrominFor very mild cases, an alternative to a bath would be the external application of Mebromin to the tetra (make sure both sides of the fish are applied to).
Product Resource: AAP Wound Control (Mebromin)

If at all possible I strongly recommend attaching a UV Sterilizer after treatment or removal of sick (or dead) fish.
This device will help in the spread of disease and improve Aquarium Redox (which improves immunity).

For more information about UV Sterilization. Please read this VERY IN DEPTH & RESEARCHED article:
Neon Tetra and FNT Disease Prevention using UV
This article explains the benefits and myths about TRUE aquarium and pond UV sterilization as opposed to the many UV Clarifiers sold via Amazon & eBay masquerading as true UV Sterilizers (most of these are only meant for water Clarification).
It is also essential for UV Sterilizer to remain effective for prevention and Redox aid, that you change your UV Bulb every six months (regardless of some claims by less than honest long life, yet low output UV Bulb sellers)

Redox Reference: Aquarium Redox

Recommended Product References:
*High Output Hot Cathode UV Bulbs
*UV Sterilizers

A medication containing Metronidazole or an additional treatment of Metronidazole in tank can be very helpful as well.
Note: this is infestation is difficult to treat and takes a "medication cocktail" approach to defeat.

In the even more rare cases of FNT disease Erythromycin may be effective (I still recommend the medicated Methylene Blue bath). See False Neon Tetra Disease (FNT) section of this article below.

Medication Information Resources:
Aquarium Medications; How Metronidazole Works
Aquarium Medications; How Erythromycin Works


It is noteworthy, based on my “house calls”, emails, customers, etc, in my years of Aquarium Maintenance & answering questions online, that the majority of Tetra Disease diagnosis are incorrect. Sadly this disease is often misdiagnosed.

Here are (in order of most common) miss-diagnosis causes of Neon Tetra Disease:

Here are a few important steps summarized to prevent both Neon Tetra & FNT Disease:

Recommended Aquarium Maintenance Companies


Treatment for FNT disease, Mycotic Diseases of Fish
I will note it is common to confuse true Neon Tetra Disease caused by the Sporozoan; Pleistophora hyphessobryconis with other diseases such as many fungi infections and often gram positive bacterium, this is called False Neon Tetra Disease or FNT Disease and is generally caused by less common gram positive pathogens.

These false infections often do not have the symptoms leading up to the white/ pale tissue and the discoloration is more faint and much less white and defined than True Neon Tetra Disease.

As with True Neon Tetra Disease caused by Sporozoans, treatment is very difficult (but not impossible) while prevention is much easier. Often the best treatment is removal and euthanasia of affected fish then following preventative measure outlined earlier.
For treatment that has any potential of possibly working, a medicated bath is an important first step.
However in tank (or better hospital tank) treatment should also consist of a primarily gram positive “cocktail” such as Erythromycin (preferably Erythromycin Phosphate, not the much less effective Erythromycin Sulfate found in the API product), possibly adding either Medicated Wonder Shells, AAP Super Velvet, or maybe Kanamycin.
AAP PolyGuard is another possible treatment based on ingredients (although I have not used it for FNT Disease).

The use of a diatom filter before in tank treatment (not during) may help, but I have had very mixed results with this extra step, so I cannot confirm this steps make much difference in an already difficult to treat disease.

Please note that these combinations (that all start with Erythromycin) are EXTREMELY hard on bio filter bacteria, so use in a quarantine/hospital tank is strongly recommended.
As lesser strength "in-tank" treatment, but less harmful to bio filtration would be Kordon Herbal Ich (& Fungus) Attack

As a side note, I have observed FNT disease (not True Neon Tetra Disease) when many cycling aid products have been used, and since many use aerobic/gram positive Heterotrophic bacteria (possibly Actinomycetes), there may be a relation.
This is only an observation, but I have noted this on several occasions with many Tetras (as well as few Danios/Rasboras), so I would cease the use of these products if FNT Disease is suspected. I should note that I have not observed this with the better Cycling aids such as Fritz, SeaChem Stability, or my preferred cycling aid; "AAP Bacter Plus".

Further Product References:
*AAP Myacin (SUPERIOR Erythromycin Phosphate) (this product is a much better choice over the lessor Erythromycin Sulfate found in API Erythromycin or Mardel Maracyn)
*Kordon Herbal Ich (& Fungus) Attack
*AAP Super Velvet Plus (also for Fungus)
*SeaChem Kanamycin from AAP
*SeaChem PolyGuard from AAP
*To aid in nitrifying bacterial replenishment after treatment: Effective Stabilized Natural Bacteria; Stability


If all these steps are followed my success rate in stopping the spread of these diseases is nearly 100% and treating early stages at around 20% for Neon Tetra Disease and 40-50% for FNT Disease.
If you cannot add the UV Sterilizer, the other steps will still help a lot, especially in stopping the spread.
But if you can afford a UV Sterilizer, purchase one, and not a UV Clarifier sold at Amazon, PetCo and others such as the Submariner or Green Killing Machine, rather a TRUE LEVEL ONE Sterilizer such as the TMC Vecton, AAP Terminator or CUP series (with prefilter)!

Water Changes are also important with both Neon Tetra Disease & FNT Disease immediately prior to each treatment. The use of the professional aquarium water conditioner AAP Res-Q is highly advised with each water change (even over other good water conditioners such as SeaChem Prime which is still inferior, especially when treating fish for disease).
Resource: AAP Res-Q

However, it is important to follow as many as possible of these steps as Neon Tetra Disease (nor FNT Disease) do not spread in the same manner as other protozoan infections such as Ich or velvet, making it difficult to treat.
This is why this “treatment cocktail” is often required and following ALL STEPS IS A MUST.

Further Reference:
Mycotic Diseases of Fish

Other Recommended Reference & Product Sites

Fish Diseases, How to Treat Sick Fish
Fish Diseases | How to Treat Sick Fish

*UV Sterilizer Reviews: Equipment to AVOID

*TMC Vecton and Advantage Premium High Dwell Time UV Sterilizers

*AAP CUP Series Submersible True UV Sterilizers

*Best Aquarium Lighting
Aquarium Lighting

The most in depth aquarium lighting article, an important read even for basic fish keepers!

*Fish Nutrition

*Aquarium Ich

*Pond Care Information

Fluidized Aquarium Filter
TMC Premium Fluidized Sand Bed Filters

Premium, second to NONE Aquarium Bio Filters, that with optional Oolitic Sand also maintain essential marine aquarium calcium levels, alkalinity, & electrolytes that are important to ALL Marine life, Goldfish, African Cichlids, Livebearers & more

Simply the BEST prepared aquarium fish food
AAP Custom Super Premium by Fish Food Guru Clay Neighbors

There is simply NO better prepared fish food; NOT Repashy, New Life Spectrum, or NorthFin, etc.
Best energy levels, best fiber content, best protein optimization, no added supplements.

AAP Spirulina 20 Fish food

Spirulina 20 Fish Food Flake

The best balanced fish flake food diet for Tetras and other fish for disease prevention


Labels: , , , , , , ,

<< Home

This page is powered by Blogger. Isn't yours?

Article Research Sponsor
Remember, it is your purchases (both small & large) at our primary sponsor, AAP, that keeps these world class information articles free.
Or please consider a donation (especially International users of this information), even just $5 usd helps.
As our primary sponsor is AAP, which provides little income for its owner after paying staff (including to help others) & upkeep of this information!

If only 10% of users of this information donated $5, this information will be able to remain free in the future!


In Chronological order of writing with the newest at the top

  1. How to Treat Sick Fish
  2. Whirling Disease in Fish
  3. Reef Aquarium Chemistry Maintenance
  4. Use of RO, DI, Softwater in Aquariums
  5. Lighting Theory of a Planted Aquarium- RQE, PFY, PAS, & PUR
  6. Aquarium or Pond Bio Load
  7. Tuberculosis in Fish
  8. PUR vs PAR in Aquarium Lighting
  9. Head Pressure in Aquarium and Pond Water Pumps
  10. Fin/Tail Rot For Betta & ALL Fish
  11. Angelfish Virus/Aids
  12. Activated Carbon
  13. Fish Baths/Dips as an aid to treatment
  14. Streptococcus gram positive bacterium in aquariums, Eye Infections
  15. Hydrogen Sulfide
    production in anaerobic De-Nitrification for Aquarium/Ponds
  16. Fish Shipping
  17. Aquarium Size, Fish Stunting
  18. Aquarium Algae,
    BBA & Brown Algae in particular
  19. Aquarium Salt (Sodium chloride) in Freshwater Aquariums
  20. Betta Habitat; Wild Bettas to Domestic Betta environment parameters
  21. HITH; Hole in the Head Disease
  22. Aquarium Protein Skimmers, Ozonizers
  23. Power Head/ Water Pump Review
  24. Molly Disease/ Mollies in an Aquarium
  25. Basic Fish Anatomy, Fin Identification
  26. Aquarium Moving/ Power Failures
  27. Octopus as Aquarium Pets
  28. Aquarium Nitrates
  29. Ichthyophonus protists, fungus in fish
  30. Aquarium and Pond Filter Media
    Types; Mechanical, Bio, Chemical
  31. Aquarium Water Conditioners (also Pond)
  32. Fish Parasites; Trematodes & Monogeneans; Annelids and Nematodes;
    Flukes, internal worms, Detritus Worms (often confused with Planaria), Micro Worms
  33. Aquarium Silicone Application;
    DIY Aquarium Repair & Glass thickness
  34. Pond Veggie Filters; DIY Bog Filter
  35. The difference between Plaster of Paris and Aquarium Products such a Wonder Shells:
    Identification, prevention & Treatment
  37. AQUARIUM TEST KITS; Use & Importance
  38. SEXING FISH; Basics
  39. Chocolate Chip, Knobby and Fromia Starfish
  40. Freshwater Velvet & Costia
  41. Usnic Acid as a Fish Remedy
  42. Aquarium Heaters; Types, information
  43. The Lateral Line in Fish, Lateral Line Disease
    or Head and Lateral Line Erosion (HLLE)
  44. Tap Water use in Aquarium; Chloramines, Chlorine
  45. Can Black Ghost Knife fish give an electric shock?
  46. Bio Wheel Review; Do Bio-Wheels really work?
  47. How do Fish Drink?
    Use of RO Water
  48. Cyclops, and Predatory Damselfly larvae
  49. Betta with Dropsy;
    Treatment and Prevention of DROPSY in all fish
  50. pH and KH problems in African Cichlid Aquarium
  51. Aquarium Gravel, which size?
  52. Blue green algae, Cyanobacteria in Ponds/Aquariums

If you have found this site helpful (or the sister site Aquarium and Pond Information),
please consider adding a link to one of our articles from your own blog or website.

American Aquarium Products along with "Aquarium/Pond Answers" (& other information sites AAP has made or purchased such as Fish Beginner), and our VAST library of information found NOWHERE else, in the world is currently FOR SALE for the right offer. As well our inventory is also part of the offer (currently as of 2021 valued at about $44,000 wholesale).
We hope to carry forward our company's 40+ year legacy of unique information (this also includes several other web and blog sites as well).

Only serious inquiries of at least $50,000 for everything (including inventory) from qualified potential buyers will be considered

Recommended Related Information Sites & Products from our family of PROFESSIONAL aquarium and pond websites:

For help with your Aquarium Chemistry:
Aquarium Chemistry; In Depth Information

World Class Aquarium Information
For unique aquatic products (most professionally tested) and information;
*American Aquarium

Free Shipping AAP

*Sponge Filters that far outperform all other brands or DIY:
*Patented Lustar Hydro Sponge Aquarium Filters

UV Replacement Bulbs/Lamps Directory:
*UV Bulbs directory

*A CLEAR POND; Care & Information

Fish Food Information:

Aquarium & Pond UV Sterilizer Use Articles
-Unique articles such as unique UV ideas as well as dispelling myths

Directions/ Instructions/Downloads; Aquarium Pond Products

Aqua UV versus TMC UV Sterilizer
VIDEO: Aqua Pond UV vs TMC AAP Pond UV Clarifier Sterilizer

A comparison of the two top large pond/aquarium-system UV Sterilizers and why the AAP/TMC comes out as the best when price and dwell time is considered

Best Aquarium & Pond Medications
VIDEO: AAP Professional Aquarium & Pond Medications


#Best Aquarium & Pond Fish Products, Grants Pass Oregon

#eBay Community Forum & Bullying, Customer Service

For Website Building/Hosting and who Aquarium Answers recommends (& uses for sister websites):
Website Hosting, powerful web site maker, ecommerce
Make a Website on

All articles are the copyrighted material of Carl Strohmeyer, these can be used ONLY in part and only with proper hyper link.
Use with Google Adwords/Adsense is STRICTLY prohibited without revenue sharing

FishLink Central

#Great Links
#Carl Strohmeyer; Biography
#Ocean Decor


For ALL questions, please refer these questions to:
Everything Aquatic Professional Forum Board