A friend of mine did a waving device for about 30 bucks with a 1rpm motor, he made it for his tunzes.
That thing works like a charm but I´m not going to try it as my 6200 would blow all the corals and sand away, but for people using smaller tunzes, I would buy a 1 rpm motor and do that thing myself rather than spending 250 bucks in a device designed to do another job.
JMHO
Marco