Fluval 13.5: Trying to keep it simple, low maintenance. Minimalist.

[olonmv]

Today, I noticed for the first time that some type of brownish algae is growing on my rock, substrate and glass. This is rather odd as it seem to have come on very suddenly. Yesterday I did a 40% water change as nitrates have been high for a while (~80) and I have been trying to gradually get them down (now ~40).

Diatoms. They’ll eventually be outcompeted by other algae.