mixed substrate

[srm1973]

Hi,

Recently bought a second hand tank, had to remove the substrate as the tank was too heavy to lift, it was aquatic soil capped with gravel, this of course means the 2 are now mixed in several buckets. Could I use this in the tank as a substrate and then cap it with playsand?

 

[roadmaster]

I think sand(smaller grain), would eventually find it's way to the bottom through the gravel, unless some means to prevent it were utilized.IME