Thanks Claire, i've had black sand in the tank for many months, I added sea glass to the left hand side and placed a mesh divider above it and threw sand in, with time the sand settled fine with a slight raise to the left so it looks slopey and bumpy. I recently bought white sand and simply added it above the black sand, so it formed a layer over the black sand. I patted the sand down to create curves or indentations, but i wanted a few black sand speckles on the white sand, so i dug some of the blank sand in certain places so it looks that way. They dont seem to be mixing, occasionally my axies dig the sand so the black sand resurfaces i just pat and push the white sand back.
(Message edited by solaris on July 16, 2005)