Most people don't like them. They normally stop the seewp motion after a short time. I have one that I have never cleaned and it still sweeps after 1+ years of operation.
That being said, theyare bulky and the flow is on the low side. Some maxijets and a wavetimer or knock off can give you a more reliable method for changes in water movement.
*180 gal Display, 100 gal basement sump, 33 gal refugium, 3x250 MH, 2x160 VHO actinics, zoos, some softies, LPS & lots of acros and other SPS.
*100 gal prop tank plumbed into main system w/ 2x96 PC lights and 1x150 MH,