u/Anxious-Lecture-2540

I’ve had 6 tank-raised otos for 2 weeks and noticed a white spot on one’s head three days ago. The spot does not appear fuzzy and the oto has been active and eating. I did a 30% water change and added maracyn to the tank in case this is a bacterial infection from a wound. Is this a wound in the process of healing or something fungal? Tank is 32 gallons with no detectable ammonia or nitrites, and 5ppm nitrate. I have a lot of plants, Indian almond leaves, rocks, and driftwood. Lightly stocked with the 6 otos, 5 rasboras, shrimp, and 2 mystery snails. Thanks for your help!