I'm taking care of my boyfriend' tanks while he is working in Germany. We have 2 a 210 and a 90 breeding tank and holding tank for some baby apple snails. The 90 has developed a white sting like algae or fungi, I'm not sure what. Does anyone know what this might be and if I need to do anything to get rid of it, and if so what. It's mostly in and around the overflow box.