Water pumps are there to pump water to your plants roots from the reservoir. There are pumps that are located in the baskets and there are pumps that top feed your plants. The DO's AND DON'TS are: DO use top feed water pumps, but DON'T leave the pump on 24/7, and DON'T pump water during the dark period. If you pump water on the top near the stems you could get stem rot, and when there is no light the water doesn't dry fast enough and can mold. I set mine on a timer to run 30 minutes out of every hour that the lights are on, and when the roots grow down into the reservoir you can set the timer back to 15 minutes out of every hour since it is feeding primarily from the bottom. And just set the timer for the water to not come on during the dark period.
Also, take one of your wife or girlfriends pantyhose and use it to cover your pump under the water because eventually it will get stopped up with rez gunk and this will prolong it's life.