looking stuff above rocks? The tank then starts to grow like a black mold on the rocks, glass, and plants. The fog kinda looks like cotton floating above the rocks. I have changed everything out each time. Its a fresh water tank and has a pretty expensive filter on it. I had 2 bubblers going at the same time I removed one thinking maybe to much oxegen. This started to happen after I moved into this new house. The house filters there water outside with just a filter cartridge. The ph is in the normal range on the test kit. I've done water changes. All my algea eaters have died off. I'm desperate, please give me some advice. THANKS: