So I started using my new tank and filter two days ago. I had the filter running for a few hours before putting the fish in, and the water parameters were spot on perfect. So no worries there. The boys have no signs of ammonia poisoning or any other sicknesses. However, I noticed that by my filter, between the two dividers, was a mass some foggy water. It was only the top of the water so I assumed it was just leftover food.
But after popping a bubble that was drifting along, I got some green slime on my finger. I immediately did a water change, about 75% and I found out that the green was only in some areas of the top of the tank, but didnt reach anywhere else. It was mainly in front of the filter and in Pudge's side of the tank.
Was it algae..? Or something worse?