This is my 3 months old sump. I made it. To hold baffles I used aquarium silicon I bought at fish store. Why is it getting so yellow and algae like. It bothers me , I know it is in sump but still... I put so much effort to make it right. And look in the second picture on left side. This is the fuge side < less flow if it matters> it is clean like new. Can somebody explain this to me please