Brown Rust like coating

I have 4 tanks, in particular a 10 gallon planted tank with 2 very small
African mixed cichlids, and 6 black neon tetras. I have been scrubbing the
glass about once a week to remove a brown rust looking growth. The pump
inlet tube also gets coated with this brown residue, as well as the Aquarium
safe polished stones and pebbles. The substrate is Eco-complete for planted
aquariums. Some of the larger leaves of some of the plants are also getting
a brown deposit. What can I do to get rid of this, without tearing down the
whole tank? The tank has been in operation for about a full month and
appears to be fully cycled at this point.

This message was written on 100% recycled spam. SAM