Now here is a topic that doesn't belong any where near a newer aquarist in my opinion.  Especially one without deep pockets or many friends to swap sand with.  Near as I can tell one needs about 3-5 times tank volume with the diversity of a rain forest to make this work well.   Yes, I am aware of the latest "Mud" concepts, etc..  Seems high maintenance to me, not to mention having no redundancy for any "crash" that may happen.  My thought is that if it isn't working well how much is it really working at all?

    Here would be a good point to mention that I do not believe that a couple macro algae, some live rock rubble, and Xenia make up a true refugium.  Even adding a mangrove or two doesn't make it such.  Course that doesn't mean that these things are bad, just that they do not complete the package of a complete refugium to me.

    That being said, I think that in the future the volumes of water maintained outside the main tank yet connected to it are bound to increase in the future.  I think that a 10 to 1 ratio wouldn't be out of the question.  RubberMaid is bound to make a small fortune.  Speculation I know, but it seems as good a guess as any.

    Then comes the ATS or Algae Turf Scrubber concept.  This again seems to be difficult at best to set up and most likely suited to larger setups than most have or will progress to.  Not to mention what happens when the whole thing goes "asexual" I believe they call it, or crashes for other reasons.  Seems this could happen with your basic power outage to me.  I must say here that I don't feel that a macro algae or three used for nutrient export in tank or a remote tank qualifies as a ATS.

    So that brings us back to the modified Berlin approach, which seems time tested.  I have noted that virtually all LFS's I have been to use this as their primary setup.  To add to that, I have visited public aquariums and the professionals there seem to set those displays up in a very similar fashion.  The difference is that they all seem to have at least some form of sand bed and very high quality hardware in the background.  As opposed to the true Berlin approach that has no substrate at all.  I would mention that many proponents of DSB acknowledge that the sand bed needs to be under 1" or over 4" depending on grain size.  One way or the other seems to be ok, but anywhere in between is apparently a bad thing.

    My opinion with respect to Man Made Live Rock is that the modified Berlin approach seems to be the best bet.  Just keep the mobile livestock out of it until the rock has matured to the point that it can denitrate the bio load you are planning.  I say wait at least a year, but it is interesting to note that those that aqua culture live rock in the ocean from dead rock seem to wait about 2 years, and that's with exposure to the wild.  So the question becomes is 1 year long enough with just seeds?  I do not know at this time, but if I ever figure it out I will surely express that when I know.