Changing gravel

[LTurner97]

I currently have gravel in my aquarium but really enjoy having catfish in my tank especially Corydoras , some people have mentioned I should change my gravel to sand as it’s better for their whiskers and bellies on the bottom, but I have substrate mixed in with the gravel , is there any easy way to separate the 2 as I only have the 1 tank so would need to be a quick job while the fish are in a container

 

[GaryE]

Be careful as what some people call sand, others call gravel. I use a lot of pool filter sand that my Cory group fish are fine with, but it's really, fine rounded gravel to my eye.