Thanks for writing these articles! I'm really enjoying them. I've been using drip systems for years. Two years ago, I replaced my entire system as many of the emitters were clogged. I use my system to both water my foundation (I live in the North Dallas area) and my plants. My biggest lesson learned is to keep the emitters suspended in free air. If you let them stay in contact with the ground, they will suck ground water back into the system when the system turns off and is draining. The ground water has a lot of "stuff" in it that clogs the emitters over time. Having them suspended also lets me do a walkaround check to see that they're all working. By the way, Rainbird has some wonderful design guides on the web. They also make a self flushing screen type filter that I really like.