I went away for 5 weeks and my mom took care of my fish for me.. She kept up with the water changes so I don't understand what this is? There is brown and green stuff on the inside of every part of the tank.. the white rocks are now green the insides of the glass are green, the filter is green.. I have no clue how it happened and she tried cleaning it off but it kept coming back.. It's a cycled 5.5 divided with two males and I've had it set up since March 10th 2011. It has 1 java fern and 1 huge marimo ball..
Can someone tell me how to get rid of it?