"The SMART DRAIN� belting is placed with its micro channel inlets facing downward so that particulate matter will not drop into the channels. "

The debris is still going to get there, using the same capillary action they are bragging on.

I agree. In fact, in my test I observed that very phenomenon happening. The interesting thing is that the water still siphoned through the channel, even with sand particulate in it. The guy at the company said that I should cover the whole system with coarse sand. This will act as a natural filter to keep clay silt out. It makes sense that since sand particals do not expand and clay silt does, even if sand got in the channel water would pass by it. Clay silt on the other hand would expand within the channel and block it completely. I'm not defending the system. I'm still not complelty convinced it will work. However, I've pulled enough standard gravel encased perf pipe with filter socks out of the ground to know that they definatley clog up. The company's argument is not that their system drains better but that it will continue to drain well after a standard system has failed. I'd love to be able to talk with someone who installed this system 5 years ago or more to see if it is still performing.

"the water still siphoned through the channel, even with sand particulate in it. "

It will eventually collect enough fines to clog.

Sand is rather coarse compared to the fines in soil.

This about like flour.
A powder.