Mixed substrates shells and sand

[DLeAnnM]

Has anyone mixed their substrates? I was considering getting 15 pounds of crushed shells, 5 pounds live sand and 15 pounds of arag-alive sand for my 20L. Any experience with this any negative side effects I should know about? I thought this way I would have a sturdy substrate at the bottom with the shells, but not too thick then sand on top.

[lgreen]

people do that all the time. keep in mind the agra alive, is not "live" and will cause your tank to cycle, if you are putting it in an existing tank.