Well i do agree that the Neptune systems are nice. But they are alittle costly. Barb i just wanted to chime in that there is a DIY alternative. I set up this system up and it basically act like a wave maker. its programable so i can fine tune the timing. It works great and as you can see alot less money. Here is a link to what i bought. Only other thing you will need is two or more power heads. They will alternate from the left side of your tank to the right side. Giving your tank the swaying motion just like the ocean. Heres the link:
SF-4005
Hope it helps and gives you another idea. I am a total DIY'er.