Cershanyx

I saw folks on AquaDoc Online Store talking about mustard algae, and it really is one of those things that tricks you at first. It looks like harmless yellow dust on the floor or walls, so you brush it off, vacuum it, think you’re done… and then the next morning it’s back like nothing happened. This type of algae hides in shaded spots, steps, corners, even around lights, and regular chlorine just annoys it instead of killing it.