the BEST substrate for refugium??????????

[CAaddict]

im in the process of making a sump. i have looked at sump/refugium styles and want to try this 1 (pic below). pic not to scale or exactly like the 1 im duin but its the closest i can find.

iv been looking around have found some competitors!

in the blue corner we have KoraLagoon Substrat Aragonite Refugium Substrate

in the red corner we have Carib Sea Mineral Mud Refugium Media

if there are any more choices please tell me cuz im not to sure at what to use,

 

[CAaddict]

bump

 

[Burto]

This is for a saltwater tank? You'd be better off asking in the salt water section.
If it's not for a saltwater tank I don't think either product is appropriate.