i don't if it is cactus sand that i'm using but what i got is like grounded white beach rocks.. but i saw some plantstore, and they are using it the same.. it is not as fine as a beach sand but the grains is finer compares to gravel. i bought it from a petshop and they said it was already processed. but still im worried cause it might kill my plants. but im using it as the top substrate(the 3rd level) and using clay for the 1st level then river sand at the 2nd level.
are you using the cactus sand for you planted tank??