So, my housings on the small boy filter that I have cracked when it froze here a while back. It took a couple of weeks to get them here to replace them. I went out the other day, reinstalled them & topped off the tank. My levels were dang near perfect. Here is the bonehead thing I did. I forgot to set my timer and it ran all night flooding the tank and changing all my levels. Also, my heater just needed to be redone so the only heat source I've had in there is a floater to keep the water from freezing. Now there is a bunch of this grey cloudy stuff that has settled over everything in my tank and the tops of the "rocks" in my beds. Any ideas? Could it be the beneficial bacteria or the algae that had built up in the tank dieing off?