The tank is 75/80 gallons, it's been going for at least 6 months. Only 2 plants in it. I'm pretty sure it's a zero for the ammonia. But the yellows look about the same on the api master kit.
This started sortly after I added two new corys to the tank. I didn't quarantine them beforehand since I've never had any issues from that pet store before. Thats why, I'm thinking it's some sort of disease.
I was guessing it being fungal due to the red parts. But i can do an ammonia treatment and get some antibiotics in the morning.
Did I miss anything?