I had thought that I would get a Tunze controller for my three Tunze 6100's and then I decided to try the wavemaker function on my Reefkeeper 2. My question is this: is their a huge difference or advantage to using the Tunze model over the RK function? Have any of you used both? Either? I'd just like some input. If a Tunze controller isn't going to do much different that my RK, then why buy another expensive piece of equipment? On another note......I really like the look of sand in a tank but now that I have really powerful powerheads, I'm finding that it's not easy to keep the sand where you want it. I'm not sure how to deal with that other than take out some of the sand and learn to live with the fact that it will be gone in the places where the Tunze are directed.