dirty rocks

[anthonys_aqua]

I've had these rocks outside for quite a while and don't remember them having these grey/black spots

there outside in the sun rain etc, wondering if this is just like weathering on the rock
wondering if there was anything bad about using them

 

[joseserrano]

Bleach them

 

[drexel]

Bleach and acid wash them like you should do to any dry rock no matter what. This is where dry rock users go wrong, they don't do both and bound organics wreak havoc later on.

 

[anthonys_aqua]

anybody got a video or link to a guide on how to do that?

 

[Jimbo327]

 

[Jimbo327]

Personally, I would just do the bleach and skip the acid.