I have a 10g tank I will be using for my fuge.I am cleaning with about 60% water & 30% distilled vinegar. I was cleaning it out earlier and got about 1/3 done when I noticed a black ink in the water. It was from the scrubber I am using. It is filter pads(unused, of course) from a HOB filter I had that I don't use anymore. Will this be harmful to fish if I put it in for a day or two once cleaned out? These are the filters I was using to clean with. Skilter Bio-Matrix Cartridges & Carbon Just the black side. They are rougher than the white. I don't have any unused toothbrushes around. Or an old credit card. Her's some pictures. Will this black in be harmful to the tank? I've already emptied it out for now. The tank. The ink from the filters. I think it is like the die from coloring?