Just read an interesting suggestion about getting rid of algae that
might be what you call "brush" - grey strands (3/4 in or so long)
forming thick soft colonies on the leaves and on the gravel.
Impossible to remove mechanically.

- KH 9
- PH =8
- No suspended organic matter of any sort - these algae seem to
benefit from it very much. So any fish that disturbs the bottom will
help the algae.

The article said it takes about 1-1/2 to 2 months to get rid of that
sort of algae.

Another thing they tried and claim it worked is to have very fine
active carbon powder suspended in the water. It settles and covers
everything and aparently does not bother the plants as much as it
suffocates that sort of algae. But having everything covered in black
powder is one ugly sight, I don't know if it works well either.

--Nikolay