Substrate for new refugium setup

[ASpec]

I'm going to add a refugium to my system this weeked and would like to know what people are using in the fuges as far as substrate.

I plan to add 3" to 4" of whatever I add. I'm considering using the Kent Marine Biosediment. I've looked a Mircale Mud... not to impressed unless someone can prove why it's worth almost $50 a bag!

So throw your suggestions/advice my way please.

Thanks!

 

[lando]

Good old LS gets my vote.