I have just installed a CPR "hang on back" refugium on my 90g Bowfront, I have done a bunch of research on the effectiveness of doing so. In all that research, some very respected individuals have all agreed that it is an excellent "upgrade" to just a trickle wet/dry system. Make sure you keep the light on the refugium 24/7 if possible. The whole package including light was under $175, I am sure you can make one yourself for much cheaper if you are handy. I guess I have no official word yet on the effectiveness, but wanted to chime in that I too have heard its an excellent addition to any filtration system.