Oli, I just use it straight out of the bag man. Nobody is sifting the sand for them in the wild in Austrailia!!! I use "Quikrete Premium" from Home Depot. Been using the same stuff for years with no issues period. I've tried the jurrasic and the reptisand stuff. And as pretty as it all is, it's a pain to get when you need it, and it's way more expensive.