ESHA 2000 – Everything You Need To Know

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What Is eSHa 2000?

eSHa 2000 is a chemical fish treatment that has been designed to treat a number of different symptoms and diseases in both tropical and coldwater aquariums. Unfortunately, eSHa 2000 is not suitable for marine aquariums. eSHa 2000 treats both primary and secondary bacterial skin infections, fungal infections as well as skin and gill parasites.

Does eSHa 2000 Work?

I have been using eSHa 2000 for the last 4 or 5 years. It is my go-to treatment whenever I see signs of infection or disease in my aquariums. I personally have found eSHa 2000 to be very effective. I have only once run into a case of a fungal infection that the eSHa 2000 didn’t treat, and that was in a large fancy goldfish.

I also use eSHa 2000 as a preventative treatment as part of my quarantine trio along with eSHa exit and eSHa gdex. Whenever I get new fish they go straight into my quarantine tank and receive the appropriate dosage of the eSHa 2000.

What Does eSHa 2000 Treat?

eSHa 2000 treats the following:

  • Shimmying Disease
  • Fungus
  • Finrot
  • Protozoan Parasites
  • Ulcers and Wounds
  • Mouth Fungus
  • Dropsy
  • Neon Tetra Disease
  • Gill problems

Shimmying Disease

Shimmying in fish, which is actually a symptom rather than a disease, is where fish rock their bodies from side to side and move in a snake-like motion. When fish are shimmying it is an indication they no longer have full control of their body or nervous system.

Shimmying is known to particularly affect Mollies and other livebearers. The main reason Mollies are affected so often is because they are usually raised at farms in water that contain either salt or lots of dissolved minerals. When we get our new Mollies home and place them into our freshwater aquariums, the Mollies’ bodies struggle to cope without the added minerals.


Fungus on fish presents itself as either a white or slightly off-white, cotton wool-like growth somewhere on the fish’s body. Fungus is usually a secondary infection and often arrives after a fish has injured itself. The fungus will also take advantage of a fish that is weakened due to other diseases or parasites.

Fin Rot

With Finrot, your fish’s fins appear sore, ragged and torn. The edges of the fins usually turn red or white. Finrot can occur when fish are kept with other, more aggressive fish or as a result of overly enthusiastic breeding.

Left untreated, fin rot will usually develop into a secondary infection such as fungus.

Protozoan Parasites

If your fish is suffering from protozoan parasites it may be rubbing or flicking its body against rocks, plants, and decor. Your fish may also appear nervous or skittish. If the fish is showing white spots then the fish may be suffering from ‘ich’ also known as ‘whitespot’.

Ulcers and Wounds

Open wounds and ulcers often appear when water conditions are less than perfect and may present initially as red patches on the fish’s body. Ulcers and wounds can also be caused by other aggressive fish, over-enthusiastic breeding, or fish having to compete for food. Ulcers and wounds, if left untreated, often lead to secondary infections such as fungus.

Mouth Fungus

With mouth fungus, fish develop a white, cotton wool-like fungus on or around their mouth. Fish with mouth fungus will eventually struggle to feed. Mouth fungus is usually caused by flexibacter bacterium.


Dropsy is the name given to various viral or bacterial infections, most of which result in the fish becoming swollen. When swollen, the fish’s scales may start to protrude from the skin. The base of the raised scales may become red as may the base of the fins.

Neon Tetra Disease

Although known as ‘Neon Tetra Disease’, it doesn’t just affect Neon Tetras. Other members of the Tetra family, as well as some Barbs and Danios, can become infected. Fish can carry Neon Tetra Disease without showing symptoms but still pass the disease on to other fish.

Fish suffering from Neon Tetra Disease may appear pale, swim in an unusual way, and become thin. The fish may develop discoloration in a distinctive ‘saddle’ shape behind the dorsal fin which will eventually spread until the entire fish appears colorless.

Gill Problems

If your fish is gasping at the surface it may be suffering from one of a number of different gill problems including infection, fungi, or worms. eSHa 2000 will treat many of the common gill-related issues.

Other Features of eSHa 2000

  • Can be used in conjunction with eSHa EXIT and eSHa GDEX
  • Can be used as a preventative treatment
  • Is well tolerated by filters, fish, and plants
  • Safe for use with snails and shrimp

How Long Does eSHa 2000 Take To Work?

I have found eSHa 2000 to work quickly. The treatment course itself lasts just 3 days, followed by a water change on day 5.

What Dosage For eSHa 2000?

The standard dosage for eSHa 2000 is 25 drops per 100 liters (22 gallons) on the first day of treatment followed by 12 drops per 100 liters (22 gallons) on days two and three.

Below is the dosage calculator copied from the eSHa website.

Can eSHa 2000 Be Used With Other Treatments?

eSHa 2000 can be combined with eSHa exit (which is used to treat Whitespot) and eSHa gdex (which treats skin flukes, gill flukes, and internal worms). I have used this trio of treatments for every fish that has passed through my own quarantine system.

eSHa 2000 should not be combined with any other treatments or medications.

Does eSHa 2000 Kill Good Bacteria?

eSHa 2000 does NOT kill good bacteria in the aquarium. It is perfectly safe to use with all filter systems and will not interrupt the cycle of an aquarium.

Does eSHa 2000 Kill Shrimps Or Snails?

eSHa 2000 is safe to use in aquariums with both shrimp and snails. I have Red Cherry Shrimp and Ramshorn snails in all my community aquariums and I have never had an issue with die-off.

Precautions When Using eSHa 2000

When treating with eSHa 2000, it is important to remove any ‘active’ filter media such as active carbon, oxidizers, and resins. UV sterilizers should also be switched off during treatment.

Caution should be taken not to overdose when treating with eSHa 2000.

It is not normally required to carry out a water change before using eSHa 2000, but if you do, you should be aware that using a water conditioner can adversely affect eSHa 2000. I always try to leave it 3 or 4 days after a water change before starting dosing eSHa 2000.

My Final Thoughts On eSHa 2000

After a number of years of using eSHa 2000 as both a reactive treatment and a preventative measure when quarantining fish, I genuinely can’t recommend it enough. I have found it to be effective and it quickly treats a multitude of diseases. I have only once had a fish that eSHa 2000 didn’t treat, but even a heavy dosage of salt failed to clear up the infection in that Fantail goldfish.

eSHa 2000 is my go treatment and my first point of call for any of the common issues fish suffer with.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James

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3 thoughts on “ESHA 2000 – Everything You Need To Know”

  1. I have a problem in my tank, looking like a bacterial issue. Been treating with api salt . Still got the problem. Looked at esha200 , is it safe to use with a water conditioner and can you use it in your main tank to treat. Will it be ok to use with healthy fish . I have lemon tetras and rasboras .

    1. Hi Karen,

      I use eSHa2000 both for bacterial issues and as a preventative treatment in my quarantine tanks when I purchase new fish. It is very safe to use and will not harm fish, snails or shrimp (I have Red Cherry Shrimp in almost all my tanks). In my experience, Lemon Tetras and Rasboras will both be fine with eSHa2000.

      As for using a water conditioner, I use Seachem Prime. According to eSHa, you should not treat with eSHa2000 48 to 72 hours after a water change if you have used a water conditioner as it can affect how the eSHa2000 works.

      I hope this helps. If you have any other questions, please let me know.


      1. I’m really worried about putting treatments in my tank. I was using salt but to no avail. My fish have had this problem like forever. They can for weeks or even months like this but it is spreading from one fish to another, rasboras seem unaffected by it. Lemons have black specs on their body and black marks on their fins so I don’t know what I’m dealing with. Some of them have frayed fins . I have tried melafix but to no avail. I worry about putting treatments in my tank in case it wipes them all out. All my tetras have been born in my tank, so not introduced anything into there. Maybe it’s something I’m doing wrong. Water changes every week. Oh 7.4.ammonia 0ppm. Nitrates 5 to 10 ppm and nitrites 0ppm. Can’t get on top of it. Just goes on forever. Tank is 125 l fluval roma

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