Despite frequent water changes and all-round healthy water conditions my stones have a dark look about them even just two days after a water change and by the end of the week are pretty black on the surface.
:help:
:help:
no it's not brown algae, my tank is well cycled and I have good water conditions. I change 30% weekly - but it's only the stones that ever look bad, water still nice and clear at end of the weekNew tank? Is it drk Brown vs. black? Does it wipe off easily? Also, do you get this on the glass surfaces also, and decorations?
If so, I would highly suspect Diatoms (Brown Algae) without knowning more about your situation. Harmless also, just looks ugly and needs to be cleaned weekly.