Coraline growing on sand?

[Bluetooth]

Doesn't really look bad, I was just wondering if anyone else has had this happen. If so, I would imagine more flow would maybe help?

[itz frank]

Are you talking about the red stuff that you can see under your sand in the front of your tank? I have this too. I don't think it's corraline but I'm not sure. If it's on top and kinda slimey(sp?) then it's probably cyanobacteria. It happens to most tanks. People claim it to be part of the maturing cycle.

[Bluetooth]

No, I have grains of sand that are purple. When disturbed, white grains are underneath.

[J. Montgomery]

My sand bed is a mixture of fine grain sand and some pieces that are 2-4mm. The larger pieces are covered in coralline, but I don't have any growing on the fine grain stuff. I hate the larger pieces and I've been trying to remove them during water changes for the past few months. . . . adding those things was a big mistake.

[mfinch99]

I have seen some sand calcify and turn into what looks like shelf rock covered in coralline.