Yeah, very interesting blog...I've always wondered how it's possible to create an artificial system without injected CO2, and still get similar plant growth to that seen in natural/semi-natural ecosystems. I've noted over the years that Darrel has achieved something similar with his high light, low-energy tanks, which I guess depend on high plant biomass and lean dosing methods.
I've done something similar, with a nutrient rich substrate, and I got fairly rapid growth, but not necessarily as compact as I would have liked. It's worth considering as well that high light can also reduce a plants CO2 compensation point, so that may help.
In my experience, I don't think it's particularly sustainable and the author keeps referring to a potential crash of the system so I'm guessing neither does he, but so far so good. I noticed that after about 3 months different species of algae started to get a hold and I started to loose the battle, but that's without the intervention of SAE and my plant biomass could have been higher which would have made the system much more robust and able to fend off algea...rapid uptake of available nutrients, shading, allelochemicals etc.
I also reckon that tannins, humic substances and DOCs released from soil based substrates and oak leaves are probably great algae inhibitors too and contributors to available CO2. So what he's advocating is entirely possible.
It also set me thinking about the whole oligotrophic vs eutrophic debate as well, and how it often tries to compare nutrient enrichment via organic compounds with that caused by inorganic fertilisers. I've never been convinced it's a very helpful comparison, especially where algae vs plant growth is concerned. One is likely to cause algae the other not so much.