I have a 55g Cichlid aquarium that is over a year old. I have always had issues with some discoloration on my rocks. This reddish-brown stuff has always been present to some extent. It is present on the rocks and on plastic items like my filter intake and outlet, but it doesn't grow on the glass. It takes a toothbrush scrubbing to remove it. I clean/PWC my aquarium on Saturdays, and it usually returns by the next weekend. I have black color quartz in my aquarium. I take very good care of my aquarium, keep the nitrates below 10, and have twice the necessary filtering. I have LED hood and usually run the lights about 10-12 hours per day. I've tried leaving the lights off for most of the day and it didn't make a difference.
What do you all think this stuff is? I've done a lot of research but I still haven't convinced myself that it's algae. Maybe Diatoms? I don't know... Here's 2 picture of it on my white rocks after cleaning. Comment please! Thanks!
What do you all think this stuff is? I've done a lot of research but I still haven't convinced myself that it's algae. Maybe Diatoms? I don't know... Here's 2 picture of it on my white rocks after cleaning. Comment please! Thanks!