Can fish get ich with nothing new introduced?

[andalite40]

I am a fairly new fish owner. I have 6 mollies and 1 little pleco with a java fern in a 10-gallon tank. I do not know how old they are or what sexes, just there are 3 big ones and 3 smaller ones. My coworker passed them off to me in a 5 gallon tank which was obviously overcrowded. I bought them the 10gal ASAP. One of the 3 bigger mollies has not eaten for the past 2-3 weeks and has a few little white flecks. It is also fairly inactive, hanging out near the bottom, but still gets around just fine when it feels like it. I did one round of API Super Ich Treatment but the fish isn't looking better. However, it is the only fish who has these symptoms out of everybody else - the rest are perfectly happy and spot-free - and I've gotten the impression ich usually comes in when you add new fish or plants. They haven't had anything added except the tank and substrate, which were all new out of the box, and it's been several months since then anyway.

Unfortunately I don't have pH stats to add. Obviously due to pandemic getting to the aquarium store isn't an option. I know seasoned fish owners have these on hand, and I will work on that when this is over, I'm just trying to do my best for these guys that my coworker's relative abandoned. I also feel like if that were the issue, everybody would be sick, not just one... right?

Anyway is it even possible that this is ich, or should I be worrying about something else? My plan is to do another round of the API treatment with daily 25% water changes and phase in some salt, not too much so as not to disturb Mr. Pleco. I can't raise the temperature too high yet because I don't have an air pump - working on that. Is this a good way to go? Other thoughts on what it might be?

 

[Aiken Drum]

Ich is generally always present in an aquarium. It will tend to affect fish that are in less than good conditions. A healthy fish will be resistant to ich.

So yes, a fish can get ich if nothing new is introduced and if one of your fish has it there is likely an underlying cause. Treating the ich will cure the problem but not the cause.

 

[Skai]

Everything Aiken said. It's very possible to get Ich without adding anything and tresting the Ich won't solve the underlying issue. Since you don't have test kits or at least not all of them. I would recommend just going ahead full steam with water changes. Water changes really can't be done too often, especially when fighting a disease. I would do 50% rather than 25% though since we don't have numbers to work with.

 

[sinibotia]

Ich is NOT always present in an aquarium. Ich must be introduced in some way. Ichthyophthirius multifilis (the parasite which causes ich) theronts (the stage of the parasite that seeks out a host fish) die without a host in about 48 hours at normal aquarium temperatures.

Pictures would help diagnose the issue. Otherwise, white flecks could vaguely describe a host of symptoms/diseases

 

[Flyfisher]

I believe both stories to be true.
I don’t have any Scientific information just a hunch .
To many old timers have stories of ich just turning up in an aquarium for there not to be some truth in the belief that ich somehow is always around. It could be eggs ( cysts ) that have a time delay on hatching? One old guy says ich comes in tap water. But he is a gentleman that says don’t change more than 25% or you will stress your fish and ich will have the chance it needs.

Many people do say ich needs a host or it dies. I say why are we fish keepers and the commercial food Industry still fighting the battle if we can kill it all no worries.

 

[Delapool]

Ich is NOT always present in an aquarium. Ich must be introduced in some way. Ichthyophthirius multifilis (the parasite which causes ich) theronts (the stage of the parasite that seeks out a host fish) die without a host in about 48 hours at normal aquarium temperatures.

Pictures would help diagnose the issue. Otherwise, white flecks could vaguely describe a host of symptoms/diseases

Plus one to above imo. This considers the life cycle as mentioned above and the crowded nature of a tank (although I have seen ich restricted to species only infections within a tank). My two cents

 

[Aiken Drum]

I should maybe clarify what i said. And this has been gone over many times before on many forums, probably on this one too. No clear answer.

I said Ich is generally always present, and i mis-spoke there. Sorry. My understanding is that it is present in "most" aquariums. As sinibotia says the Ich parasite will die out quickly without a host. So a fishless tank will be ich free and ich would have to be introduced. If strict quarantine including treatment is followed then you can have an ich free aquarium. But lets be honest, most people dont follow strict quarantine and so most aquariums will contain the ich parasite, and healthy fish carrying the parasite arent likely to result in the disease. A fish could carry the parasite for a long time before an underlying cause/health issue results in symptoms.