Bubbles

[Jaws]

I got home from work about an hour ago and realized that there were a bunch of tiny bubbles that had formed all over the back wall of the tank. I basted them all off along with the rock at the same time. I went back in to have a look about an hour later and there were even more bubbles this time as well as the copper looking stuff that I siphoned off of the sand bed yesterday was already coming back pretty noticably and even some of the rock is looking rather copper-like. There's no bubbles being created or circulating in the tank to cause this problem either. Any ideas?