I have 40lb CC
and 40lb LS
is obviously on top. Works well enough for me and the white sand enhances the color of the tank.
What was the purpose of adding the sand? CC
collecting too much buildup? Dont like the way CC
looks? If you've had it for 7 years it can't be all that bad. If you're just looking to increase the depth of your sand bed then heck -- dump in sand on top of things -- it looks good to me