I think I might have found the problem. I had two artificial tree stumps and a large artificial rock in the tank. I would move them around and clean underneath their spots in the tank. Then I was removing the african cichilds to put them in my new tank and found that these decorations were holding ALOT of gunk. I always feed my fish away from my filter intake and these stumps were right below the area that I feed. I think the smaller particals of food and fish waste were settling down into the hollow parts of these stumps and causing the problem. So I have just removed them for now and I'm planning on getting some driftwood and live plants. There's not much in the tank as far a decor now without these but I'd rather the water be clear and clean.