Urgent What's WRONG with my poor Cardinal???

It's probably some kind of fungus, It's definitely not Ich. Ich will look similar to little flecks of laundry detergent (the powdered kind). If he's eating you're probably fine and it will run its course. A good first measure would be to do a little more frequent water changes (small) 10-15%... At least that's how I attack a problem when it comes up.

If it doesn't clear up in a week or so you can try a bunch of other things all of which are a real pain. Keep us posted

 

thanks again for the continued help everyone. I agree that it's def not ich, I'm 97% sure it's lymphositis which will run its course. reading up on it seems like it will survive but I'm keeping a watchful eye on it, I have no QT but am monitoring its progression.

Having to catch it and bring it to a QT elsewhere would just stress it out more, lower the immune system, I will let it be and continue feeding and monitoring it. I do hope none of my other fish develop a severe case of it, it's spread by direct contact and I'm sure some of my others have lesser cases of it by now (that they should be able to get rid of over time).

 

My suggestion is soak the food in garlic if it's not eating, do daily water changes, and check parameters constantly. I think it's up to the cardinal's immune system now. Best of luck to your Cardinal, I hope he can get through this!

 

If you plan on not putting it in quarantine I would do as others have suggested with the soaking of food in garlic. Also feeding extra will help as that helps build a fishes immunity to parasites. If you ate going the qt route I recommend Prazi-pro for the treatment of worms both internal and external. Good luck, hope he make it!
Heidi