In my planted tank I don't clean off the back. Partly to give the MTS and Amano shrimp something to munch on and since I am using a black trash bag taped to the back of the tank (black background ghetto style), the algae magnet does not maneuver back there too well. Plus the filters present and obstacle. Also, some stray java moss has grown onto the back wall in a few spots to create a partial moss wall.
In my shrimp tank I only clean the front pane. I want to leave as much biofilm and algae for the baby shrimp.
Not sure if the algae impact the plant nutrient supply. In the planted tank I heavily fertilize it and in the shrimp tank it only get root tabs every few months.
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