A few days ago, I noticed this brown discoloration of some of the decorations in the froggy tank. Today, I finally realized it was brown algae and the tank got it's first scrubbing, inside and out because I know that stuff can take over a tank in no time at all. EEEEWWWWWW!!! Little frogs poop a lot, y'all! I thought, since the tank is half bare-bottom and rocks are only in part of the tank, that as long as I fed them over the glass, and kept the poop and extra food regularly sucked up (using the turkey baster, still haven't justified in my own head the expense of one of those fancy dancy gravel vacuums) that it would be pretty clean. okay then... so today I decide to really clean the tank. I started by sucking up any gunk from the edges of the rocky places. Oh, that was nasty. Really really nasty brown goopy grossness. EEEWWWWW - so I wonder what is under the rest of the rocks and get to cleaning everything really really well. I got three gallons of dark brown gunk from under the rocks and decorations, which I used to water my houseplants, they should love it. I scrubbed the brown slime from the food dish and hidey holes, then realized there was brown gunk (algae) growing on the glass, too. *sigh* It looks as though I've been greatly overfeeding the little frogs and undercleaning the tank.