Can Plecos Get Ich? How To Treat Pleco White Spot

Last Updated on January 19, 2022 by cmoarz

Can plecos get white spot (ich)? It’s something you might be wondering just because, Or you might be in a situation where you suspect your pleco has ich and now you need to know whether that’s possible or not, and if so, how to treat it.

Right off the bat, It’s important to know that Pleco’s can get ich. In fact, every fish can become susceptible to ich, and there are many reasons why they get it.

But not all fish can be medicated like others, as some have sensitivities that make it difficult to treat ich.

In this article, We’re going to take a look at some of the common causes that expose your fish to the ich protozoan, what you can do about it, and whether or not you should use medication when treating your fish for ich.

What Is Ich?

First, a quick rundown on what ich is. (You can skip this section if you already have a strong grasp of the ich life cycle which is important to know)

Ich (ichthyophthirius) is a common skin disease that’s caused by a ciliate protozoan and affects many types of freshwater fish. It can be transmitted through direct contact or contaminated water and food.

Ich appears as tiny white spots on the body and fins of infected fish and can be seen with the naked eye.

These white spots are the parasites themselves nestled inside a cyst that the fish body creates as a defense.

This parasite stage is called trophonts, which feed on the skin cells and other tissue fluids of fish. In high numbers, these parasites clog up the body of a fish to the point where they interfere with bodily functions and eventually kill it if not treated.

It’s important to understand the life cycle of ich as that’s the best way to kill it. This is what you need to know.

Life Cycle of Ich

The life cycle is as follows: the parasite attaches itself to the fish and feeds on its bodily fluids, emitting a protective layer around it as it grows in size.

This is called a “tomont” stage and can be seen with the naked eye as a white spot on the fish.

Tomonts eventually break off from the host and fall to the bottom of aquariums (or ponds), where they develop into a second stage called “trophont” ich parasites.

Trophonts form into swarmers that break away, swim-up towards the water surface, and become free-swimming.

These free-swimmers are what we call ich (or the “white spot” stage). These trophonts will now seek out new hosts to feed on and continue the cycle.

It’s important to understand that this entire life cycle takes place over an average of 10 days but can occur in as few as 5-7 days, or up to 3 weeks.

Within this time period, there’s a significant chance of the disease spreading throughout your tank. For this reason, it is important to medicate all fish very quickly after noticing ich on one fish.

It’s also critical to understand that if you do not medicate your entire tank, the “free-swimming” ich parasites will survive and reproduce. These new trophonts will attach to other fish and start the cycle again until you eliminate them with medication.

Heat can decrease this 10-day life cycle considerably. If the parasites do not find a host within that timeframe they will die.

During this stage is when the parasite is most vulnerable to medication and heat treatment.

I know this was a long introduction, and perhaps something you already knew, But it’s important to have a good, solid grasp on what ich is before venturing into treatment.

What Does Ich Look Like on a Pleco?

Ich will present itself as tiny white or grey spots on the body and fins.

A heavily infected fish will often have hundreds of these spots all over its body and may have what we call “ich bloat” because it looks like it’s swollen with fluid, but it’s actually the blocking of bodily functions by the parasites.

The early stages can be seen when the fish starts “flashing” which is another fancy word for “flipping” around on the bottom of the tank, rubbing itself against rocks and often darting around erratically.

This is actually a behavior that they do when there are parasites on their bodies that bother them to an extent that they need to get rid of them, similar to us scratching at mosquito bites.

While this is one of the first stages of infection, it’s also one of the hardest to diagnose because many parasites cause this type of behavior even if the fish is healthy.

In a healthy fish, Often times symptoms won’t progress past the flashing stage. Ich really only takes hold if a fish is stressed, injured or its immune system has been weakened.

That’s not to say you shouldn’t deal with it as soon as you see it starting, because you should. Eventually, the ich will take hold. And if one fish has it, all fish in the aquarium have it.

Are Plecos Sensitive to Ich Treatment?

As scaleless armored fish (catfish) plecos are somewhat sensitive to most ich treatment medications. This is why the heat and salt treatment method is preferred, although medications can be used, often at half doses. You can read more about that here.

How To Treat White Spot (Ich) In Plecos

There are 2 main ways to treat ich in plecos. Heat and salt, or medications such as dosed PraziCure.

The main thing to remember during any ich treatment is to be patient and allow the full suggested time for the medication to run its course, regardless of whether it’s heat or meds. Too many people want fast results and will shorten the amount of time necessary to completely wipe out the parasites.

Heating Your Tank for Ich Treatment

Heating your tank is probably the most popular method of treating ich in plecos because it’s very simple and straightforward.

To treat your tank with heat, You will need to add 2 teaspoons of aquarium salt per gallon of water (taking into account substrate displacement). Don’t worry, your freshwater fish will easily be able to handle this amount of salinity, however, your ich parasites will not.

Dissolve the salt ahead of time before trying to evenly distribute it into the water column so there are no strong salt spots.

You will then need to increase the heater in your tank to 30c (86F) for a full week. This will speed up the ich cycle and allow the salt to kill it faster.

Because this higher temperature is stressful, you should monitor your fish for abnormal behavior and watch for the stress of fish that are particularly sensitive to this sort of treatment.

Whether you use medications or heat treatment, the tank should be monitored after completing your treatment. If there are still ich parasites present they will come back to life and start swimming around again.

For medications, simply follow the directions on the bottle, But in most cases cut the dosing in half for your plecos sake.

When using medications, don’t forget to remove carbon from your filters or any other filtration media that you might be using. Carbon will remove most medication very effectively and either lengthen the treatment time or reduce its effectiveness.


Owner of and also owner of actual Aquarium Gravel believe it or not! ;). Setting up beautiful aquarium sceneries and habitats since I was very young. Enjoy!