I couldn’t agree more. That rock in the original post is about as clean and sterile as rock can be. I don’t see a spec of nasty on there. And the “nice and white” phrase lends me to believe there’s a misunderstanding going on about what rock should look like in a thriving tank. White rock = dead rock. The whiter it is, the more biologically poor and unstable the tank is.
Yes...rock covered on green hair, bryopsos, and bubble algae isn’t the ultimate goal, but even those unattractive algae do serve a purpose and if you approach the tank correctly they’ll be gone on their own really.
This is an excellent example of super healthy rock that if you filled the tank with this, you’d have as stable and mature of a biofilter as you can imagine. Note, not a spec of white on it
You folks with new tanks worrying you’re going to lose the pearly white look to your rocks....good, that is the idea