Is this the correct kind @derek420colorado ? If so, do I just sprinkle it on top of the soil a little bit or do I have to use a 1/4 inch layer all over like the sand? http://www.homedepot.com/p/Garden-S...u58p7XuXcyZftPM8aR-q7hoCsHbw_wcB&gclsrc=aw.ds