Why Glofish Has White Spots?

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Glofish are astounding fish that will make for an exhilarating addition to any aquarium. This category of fish has grown in popularity drastically over the past several years thanks to its unique look and ease of maintenance.

As you know, Glofish are a category of fish comprising 5 different species. These include bettas, zebra danios, tiger barbs, rainbow sharks, and tetras.

Their popularity stems from their fluorescent coloring, which is the result of genetic engineering. Other than their peculiar glow, Glofish are just as easy or difficult to maintain as their non-fluorescent counterparts.

They require identical living conditions, diets, and overall care and maintenance, and they also have similar lifespans.

Since their coloring isn’t the result of artificial injections or chemical procedures, their overall lifespan remains unaffected. The Glofish’s genetic modifications have only impacted its coloring and nothing else.

The Glofish can now pass on its fluorescent genes to its young, provided both parents have them.

That being said, Glofish are still vulnerable to pretty much all fish diseases, one of them being Ich (White Spots). Today, we will discuss this condition’s profile, what causes it, and how to treat and prevent it from keeping your Glofish safe and healthy.

What is White Spots Disease (Ich)?

Ich is a parasitic infection caused by a protozoan called Ichthyophthririus multifiliis. I, know, it’s quite a mouth-full, which is why we call it Ich to save us the trouble. This protozoan is quite aggressive, and it can spread and kill all fish in the tank rather fast.

One of its main symptoms involves white and blistery lesions on the skin, hence the name.

The problem is that the white spots may not always be visible. If the condition is limited to the fish’s gills, there will be no white spots visible. This will make the condition slightly more difficult to diagnose and treat in time.

To better understand the disease, let’s analyze its cycle:

  • The Trophont Phase – The trophonts are late-stage protozoan organisms that detach from the dead fish and attach to the tank’s wall and substrate. It will then enter a reproductive phase that’s similar in concept to the butterfly’s pupa. The trophont will surround itself in a cyst wall, carrying the organism into the next phase, the tomont.
  • The Tomont Phase – This is the phase where the tomont begins cellular division. It will split into multiple forms called theronts, producing between 100 and 1,000 such bio-components, depending on how large the cyst is.
  • The Theront Phase – When the cyst was reached its maximum size, it will burst, releasing the hundreds of theronts which will immediately swim away in search of live hosts. Those would be your oblivious Glofish. The theronts will survive approximately 2-3 days in the tank’s water until they will either find a viable host or die. If they will find their host, they will bury themselves in the victim’s skin and transform into trophonts. These organisms will feed on the victim’s tissue until they mature, exit the dying or dead host and reset the reproductive cycle.

The problem here is that one mature trophont can give birth to hundreds to 1,000 theronts or more within 24 hours. So, the infection will spread fast and can take over your entire fish tank before you can realize its presence.

An important aspect to mention here is how the cycle works. Basically, Ich isn’t contagious at all times. It’s only contagious when the theronts have been released into the water.

So, if you spot white spots (heh) on your fish, that means that the disorder isn’t contagious yet.

Are White Spots Contagious?

Yes, Ich is contagious in the sense that one infected host will release the mature trophonts, which will multiply into theronts and infect other healthy fish fast. When it comes to adequate treatment, fast is the name of the game. The sooner you address it, the more chances you’ll have of saving your fish.

The problem with White Spots is that it doesn’t discriminate. It will infect all fish it can reach, no matter their size, species, or how healthy and strong their immune systems are.

How Ich Gets into Your Tank

Ich typically lands into your tank on infected equipment, plants, and fish. The latter is more prevalent since fish are natural carriers of the protozoan.

This goes to show that verifying your fish prior to introducing them to your already established tank is ideal for preventing scenarios like these.

It’s even more important knowing that Ich doesn’t always display visible symptoms, at least in the first phases. So, next time be careful where you’re buying your fish.

Fortunately, Glofish are a trademark product, and you’ll only be able to buy them from certified sellers. It’s unlikely that they will come infected with Ich, but you never know.

How to Treat Glofish with White Spots?

First, I recommend quarantining the sick fish as soon as you’ve spotted the first symptoms. If your fish displays white spots, it may be safe to assume that there are no free theronts in the water yet.

At a minimum, quarantining the sick Glofish will eliminate one source of infection, even if other fish are sick.

After that, there are 2 viable options when it comes to treating the condition:

  • Chemical treatment – This method is optimal when performed during Ich’s tomont and theront phase. That’s because these organisms are still in the water and haven’t infected the fish yet. Once it has reached inside the fish and turned into trophonts, the treatment’s effectiveness will drop significantly. Most medications used to treat Ich contain copper sulfate or formaldehyde, among other components, so I recommend discussing with a professional to figure out the best medicine for your Glofish.
  • Raising the water’s temperature – Once you’ve quarantined the Glofish, you can increase the water temperature past the protozoan’s comfort zone. The parasite’s life cycle lasts approximately 21 days from trophont to theront, and the reproductive process rests heavily on the environmental temperature. This is the standard duration of the cycle at 50 F, so you can increase the temperature as much as possible to speed up the protozoan’s life cycle. Just make sure your Glofish can withstand the higher temperature otherwise, it may experience a temperature shock. And increase it gradually since most tank fish doesn’t sit well with sudden temperature fluctuations.

Part of the Ich treatment is changing the fish’s water daily, providing your ill Glofish with impeccable water conditions and a balanced diet during quarantine.

The treatment should last around 5 to 7 days, by which time the Ich protozoan should have been eliminated.

How to Prevent Ich in Your Glofish?

It is possible to prevent Ich, so long as you know what to do. The most obvious prevention mechanism involves ‘sterilizing’ any new equipment, plants, or decorative elements supposed to go into the tank.

It’s not a genuine sterilization process but rather a circumstantial one. You only need to keep the plants and the tank decorations either in a quarantine tank or outside the water completely.

The theronts won’t survive the past 3 days without access to any live host.

An equally important prevention tactic refers to quarantining any newcomer fish prior to placing them into the main tank. This will allow you to assess their condition and make sure they’re healthy to avoid any unwanted surprises.

The quarantine period should be around 7 to 14 days, which is enough for Ich to display its symptoms if present.

Also, keep in mind that early detection is key to any reliable treatment. This means you should always monitor your Glofish for any signs of disease and act as soon as you observe worrying symptoms.

Can Glofish Die from White Spots?

Yes, they can. Late-stage Ich almost always kills the host, which is why early prevention and containing the disorder are such important factors.

The good news is that Ich isn’t always fatal. Your fish can recover, provided it receives early treatment.


Ich is a scary condition, especially for novice Glofish keepers who haven’t encountered the disorder before.

However, you only need a bit of know-how and confidence to diminish the disorder’s scary factor.

I hope this article has provided enough of the former to boost your confidence significantly as a result.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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