Ich is a nasty parasite that can attack your fish and could kill them if left untreated.
In this article, we are going to explore what to do if you have had Ich in your tank and how long it might survive in different situations. Let’s look at aquarium Ich survival: 9 things you should know!
Once you have removed the fish from your aquarium, the Ich will no longer have a host, but it can survive for a long time. Which phase the Ich is in will have a big impact on how long it lives. In its longest phase, it can survive for up to 72 days without a host.
Let’s learn more about aquarium Ich and how it behaves in your tank.
1. Can Ich Survive Without Fish?
Ich can survive for a certain amount of time without fish, but not indefinitely. It needs to feed on fish or It will die.
This parasite is not able to survive in a tank with no fish, because it will have no viable source of food. If you have lost all your current fish stock, it is advisable to wait before adding more, or they will get reinfected.
Leaving the tank without fish will prevent the Ich from surviving and spreading to the new batch of fish when you add them. This is one of the most effective ways to deal with an infection if you cannot save your fish.
Read More: Can Fish Survive Ich Without Treatment?
2. How Long Can Ich Survive Without Fish?
This parasite needs to feed, and in some phases, it will die quickly if there is no food available. In other phases, however, it can last for weeks.
There are 4 phases to this parasite’s life cycle:
- Trophont (while parasitic and attached to the fish)
- Protomont (while in the substrate, reproducing)
- Tomont (the reproductive phase)
- Theront (swimming in search of a new host)
Many of these phases cannot survive for long without a host – for example, the Theront will usually die if it doesn’t find a fish within 24 hours. However, the Tomont phase can last for much longer. In extreme cases, it could survive for 72 days with no host.
Some people use 30 days as their guideline, while others use 60. It is rare for Ich to survive beyond 60 days, but it is possible.
Be aware that the Tomont can be invisible in the substrate, and you will not be able to tell that it is there.
It causes many hobbyists to think that they have successfully rid their tank of Ich, only to have it return.
3. Can Ich Survive Out Of Water?
You might think that draining your aquarium and leaving it to dry out would be an effective way of killing off Ich. Unfortunately, this may not be the case.
Some sources do recommend drying your tank and then sterilizing it and its contents as a means of killing Ich. However, the fact that sterilization is recommended suggests that Ich will not be reliably killed by drought alone.
To be clear, it is likely that being kept in dry conditions would kill Ich, but it’s hard to say how reliably. It is also difficult to effectively dry all the components of an aquarium.
If you drain the tank, water will remain in the sand, live rocks, and all the nooks and crannies. Getting it completely dry for a set period would be difficult to measure and could prove ineffective. Many people claim to have had an Ich infection from equipment that has been dried for months.
In summary, Ich probably cannot survive out of water for more than a few days, but this isn’t a reliable way to kill off this pest. There are better methods.
4. How Long Does It Take For Ich To Die In Empty Tank?
If you want to be safe, you will need to run a fallow tank for at least 6 weeks.
That might seem like a long time, but it should help to ensure that the Ich has died off. Some people even extend this to 8 weeks for extra safety and to ensure that the Ich has minimal chance of recovery.
Because the longest that Ich can survive in its most resilient form is 72 days, this is the absolute maximum that you should need to keep a tank fallow for. That means the Ich should certainly have gone.
Some people state that this sort of time period is overkill and unnecessary, but there are reasons to go overboard in this scenario.
If you add fish back to your tank and it is still infected with Ich, you will be back to square one immediately and all your work so far will be completely wasted.
That means the weeks of hospital tanks, treatments, and an empty aquarium will have been for nothing, and you will need to do it all over again.
Additionally, your fish may already be stressed (assuming you are not starting with new fish) and may be more susceptible to parasites as a result.
For many people, it is therefore worth waiting a few extra weeks to avoid the risk of starting all over again. That means waiting out the Tomont’s maximum lifespan before you put fish back in your aquarium.
You can see that this study on Cryptocaryon Irritans Infections states that an average life cycle is only 1 to 2 weeks, but that Ich can endure for 11 weeks because the Tomont development is unpredictable.
That means that 6 or 8 weeks is usually plenty for killing off Ich, but that if you want to be really safe, you need to wait longer. The same article mentions that Tomonts can survive for 72 days in some situations.
5. How Long Can Ich Survive On Plants?
A couple of the Ich’s life cycle stages can survive on plants, which is something you need to be aware of before you add any new plants to your aquarium. If you aren’t careful, you might accidentally introduce Ich with this additional foliage.
The safest way to deal with this is to quarantine your plants in a tank with no fish before you add them to your main aquarium.
You can usually do this for just a couple of weeks and this will be sufficient to kill off the Ich.
There is a chance that it will survive for longer if it is in its Tomont phase, but this is unlikely, and you can then transfer the plants to the main aquarium.
Some people prefer to do a bleach dip as a means of killing off any unwelcome hitchhikers on their new plants, but this can kill the plant too. Most plants don’t like even diluted bleach, and if you dilute it too heavily, it won’t work on the pests.
Quarantine is therefore the best option for preventing Ich from being transferred to your aquarium by new plants.
6. Can Ich Live On Dead Fish?
It is unlikely that Ich will remain on dead fish for long. By the time the fish has died, the parasite may be ready to pass into its next phase anyway, and will not remain on the fish. Additionally, dead fish attract predators, which the Ich would need to avoid.
If a fish dies, it is likely to be picked up and eaten by a larger fish pretty quickly. Any Ich remaining on the fish would be eaten too. It is therefore better for them to drop off, even if they have not moved into the next stage of the life cycle.
You are unlikely to find Ich on a dead fish for more than a day or two after it has died. You should still remove all dead fish from your aquarium to prevent them from rotting and poisoning the water.
7. Can Ich Live On Snails?
Ich does not eat snails, but snails can carry these parasites.
The parasites are tiny and can easily cling to the shells of snails, so you need to be careful if you are going to add snails to your tank.
Ich can attach itself to all kinds of different surfaces and may survive for long periods, even if it doesn’t have a viable food source (depending on the phase that it is in). Any item or creature you add to your aquarium could theoretically carry Ich, therefore.
If you are going to add snails to your tank, you should quarantine them first. This is the best way to minimize the risk of introducing Ich. Keep the snails quarantined for at least 2 weeks before adding them to the main aquarium.
8. Will Ich Eventually Go Away?
You may have noticed that Ich – which appears as white spots on your fish – suddenly disappears sometimes. That might prompt you to wonder whether this parasite can ever just go away on its own, without treatment from you.
The answer is that it’s pretty unlikely.
Many people theorize that Ich is present in almost all aquariums, but it’s only when the fish get stressed that it becomes a real issue. Some people dispute this claim and say that Ich is only present when introduced.
Either way, Ich is not likely to disappear from your aquarium without treatment. If your fish stocks are healthy and not stressed, you may rarely notice the Ich, and it can be undetectable while it is in certain life cycle stages, but it will not actually be gone.
If you have an Ich infestation, don’t try to wait it out.
It will kill your fish if they are stressed or sick, and may attack healthy fish too. You will need to quarantine and treat the fish, and keep the tank fallow for a while to get rid of this parasite.
9. Fish Died From Ich: How To Clean The Tank (Helpful Tips)
If you have recently lost all the fish in your aquarium to Ich, you will need to clean and sterilize the tank before you can add more. If you don’t, they might suffer the same fate.
You have a few options for cleaning your tank. If you want to, you can start completely from scratch, emptying the entire tank, scrubbing it with bleach, and getting new substrate, new plants, and new inhabitants.
This method is effective, but expensive and time-consuming.
You will have to spend a long time reestablishing the biological filter, restarting the nitrogen cycle, and waiting for the aquarium to stabilize. This often takes around 2 months or more.
Alternatively, you can make sure you kill the Ich by running your aquarium fallow at a reasonably high temperature for a set period. To do this, remove all the remaining inhabitants, empty the tank, and refill it with fresh water.
Next, restart your tank filters and feed your biological filter a bit. Increase the temperature to 75 degrees F to encourage any Tomonts to hatch into Theronts. These will then need to find a host quickly, and when they fail, they will die. This should take about 10 days in total.
Change the water again and stabilize the aquarium before you consider adding new fish. Make sure you are doing water tests and that the conditions are suitable.
Ich attacks fish that are stressed and being kept in unsuitable conditions, so if you make sure the tank is as suitable as possible, you will reduce the risk of the Ich taking over.
When choosing your new fish, choose energetic, healthy specimens and quarantine them before adding them to the new tank.
This will minimize the risk of problems and should prevent the Ich from killing your new fish stock. If you are still having problems, talk to an expert about the specifics of your setup to see where the issues may be originating.
Ich can be enormously troublesome and many hobbyists face this frustrating parasite at times. It is extremely difficult to treat effectively. Knowing how it behaves, how to quarantine tank additions, and how to refresh your tank after a bad infection is crucial to aquarium ownership.
Hi! I’m Praveen Ghoshal, the founder of eFishkeeping.com. Inspired by my Dad, I got interested in fishkeeping when I was a kid. Since then, I have been involved with this hobby. Currently, I have 3 fish tanks at our home, where I enjoy this hobby with my Mom, Dad, and Younger Sister. Read more about me here.