So I think I have black mold or mildew inside my sump. Some is black and some is reddish. Its in the corners of my sump and along the silicone on the baffles. I try and scrape it off and it doesn't come off but my fingers smell very musty like mold/mildew. I'm very perplexed because its inside under the water, What is it and is it going to hurt anything? The tank is recently setup about 1.5 months old 5 fish in the DT with no signs of stress.