I just put a new VorTech MP20 in the RSM, and I am very impressed with it! I'll be doing more playing around with the different modes and settings later, but it's creating flow in every part of the tank. I have it on short pulse mode now, which creates an adjustable frequency between minimum and maximum speeds, and is creating wave action on the surface. As I've read, the flow is very broad, so even at a max of supposedly 2000 gph it isn't blowing things off the rocks. Does a great job of suspending detritis too, so it can be pulled into the filtration section. Along with putting the Vortech in, I also gave the tank a good razor scraping, replaced all of my chemical media, and remounted some corals, including attaching a Palau Nepthea frag I had been growing out on my frag rack. So, my corals were all a bit "upset" with all the tank maintence going on, and many of them are sliming a bit, but the new pump is doing a great job of removing the slime and keeping it suspended till it gets filtered out. I can no longer see any dead spots in the tank. The coralline encrusted Koralia has been retired! So far no negatives on the Vortech, and it's very quiet. Amazing what a single pump can do!