I've Got GNATS!

I have 8 plants under a 400 watt MH in my closet.. the plants have been growing very well, they are about 8 inches tall now still in their vegitative stage. everything has been going smooth, However I noticed in the past week or so that gnats have made their home in my grow room.. every morning there are more gnats. I have been spraying them with plant friendly Raid, but they just keep coming back. They seem to like to hang out on the dirt ( possibly because i have a fan on the plants and they cant land on the leaves...). I am wondering how I can get rid of these little fuckers once and for all. what is the safest natural pest control product out there?? any suggestions/help would be appreciated. Thanks!

Stop with the raid!!!! I swear by the potato slice. You put a slice of potato on your soil then you leave it for a day they are drawn to it. Then you take it flush it or get it out of the house, and then just do it again and again until they come up clean a couple of times. I find it's a bad watering practice, you may be keeping your plants too moist. Let the soil dry out before you water them. Also there will be people who say put sand on your soil thats fine but you gotta get the gnats out of it before you do that. If you find your having a problem on the leaves go the neem oil route there are several threads on how to use it. Good Luck to you!

A half inch of sand on the top of the soil works very well for me.

Thanks... im going to go buy some sand from home depot and put it on the soil today.