Brownish coloration all over

[Hethari]

Hello
I have breakup of brownish material all over sand rocks all my reading are ok help please

 

[RMS18]

Looks like dinos but need a better picture without the blues. Can you describe the brown material?

 

[Hethari]

Blown away easily and exactly like rust

 

[RMS18]

Dinos. I am going through the same thing. I have dino-x on it's way. I tired the 72 hour black out and po4 was in check. During the 72 hour black out I took out half my sand and laid down new sand. It came back a bit not nearly as much but it's back. Gonna give dino-x a try now.