2 cory catfish with ammonia poisoning?

[Fish obbsessed]

I have 5 cory catfish in a tank, 2 of them randomly have ammonia poisoning? the tank is cycled and the highest my ammonia and nitrites have ever been is 0.3ppm, i dont think 3ppm is enough to give ammonia poisoning. Its also a bit strange that only 2 corys are infected. They are getting better, i noticed the red has been fading away and there starting to breath much better. They are getting better but its still a risk:/. i also want to know how that got the poisoning i the 1st place? I only added the fish a week ago. Its my 3rd tank.

 

[Aiken Drum]

If your ammonia never got above 0.3ppm ammonia they arent suffering from ammonia poisoning. The only way ammonia at that level is harmful is if it is also accompanied with off the chart pH and then whatever caused the extreme pH would kill your fish before the ammonia.

Whats possible is you had a much bigger ammonia spike a few weeks ago and didnt notice. Ammonia poisoning tends to take a couple of weeks to show symptoms.

Otherwise it could be something else. Infection in the gills and parasites can cause similar symptoms.

Do you know your other water parameters?

 

[ColdKoi]

I’d definitely have to agree on that one because I’ve seen it first hand.

By the time the fish shows physical signs of the ammonia spike (unless sudden and extreme) the spike may have already come down or even be completely gone!

I’d be keeping a close eye on the fish and water parameters. If the water is keeping steady and healthy you may have or had an infection/parasite