I noticed over the past couple days the one of my oscars has what seems to be a hole on his head. I was wondering what you guys think, any info helps, thanks. Im not able to check parameters until tomorrow but last time I checked it was 0 ammonia, 0 nitrite, and looked like 20-40 ppm nitrate but more towards the 20 ppm color. I do 30% water changes every week since I got them about a year and a half ago





