Can someone explain to me the difference between regular DE and the DE that is used in swimming pools? I thank you ahead of time for any answers.

The swimming pool DE has been heated and is in a different form and is in no way safe to use in an organic landscape. Be sure to get only the natural DE to use.
Richard Spitzer

The Swimming Pool variety of DE it has been processed, and is some cases chemicals added and the edges are not as sharp. Use the Horticultural or "natural" type. This has not been processed, the edges on the shells are still sharp and it will not harm your kids, dogs, cats, horses, etc.... DE is actually the shells/exoskeletons of tiny diatoms. the edges are extremely sharp, but small. as insects like pill bugs travel across it their exoskeletons are cut and they eventually dry out and die. this stuff is good (to get rid of) for all insects.

Dustoff79,
Thank you for the DE explanation. It made sense. I had already used some of the swimming pool DE on a few ant beds I saw. It reminded me of flour. It wasn't effective at all and now I understand why. I did use a little bit of orange oil in a gallon of water on the ant beds and it really worked great. Thanks again.