Hello, I recently had an outbreak of this brown stuff on my sand and I'm unsure exactly what it was. So my tank has been running since February and it was barebottom up until 2 weeks ago. I decided I wanted to add sand bit by bit and I'm assuming this is diatoms but I can't tell for sure. I'm assuming that if you add sand, you kind of "start a new cycle" in your tank and that could be why diatoms are forming. It only seems to cover the sand and nothing else, that's why I believe it's diatoms and hoping it's not dino algae. Any input on what it could be?
