Gotta say I love it. Was planned/built for over a year before you took pictures (No offense to those who do go through the long drawn out build phase posts), so we get somewhat instant gratification.
Always something I wanted to do, however the thought of the power used on heating that system just gives me shivers.. I know you say it doesn't cost very much, but I could imagine building the whole thing then getting a huge sticker shock on my electricity bill after the first month of it on. Not to mention doing water changes on a system that large has to be a pain in the butt, at least here it would be.
I am curious on specifics of equipment, like pumps and skimmer, I know you said early you use a big bubble magus, custom made big? Or do they make stock skimmers that large? Although your pumps might be a brand that isn't available in the US, would be nice to try out those really large Tunze models on something that large though.
Kind of scary tank with those sea cucumbers which look huge in the tank, and the tangs which look absolutely tiny, gives me nightmares thinking about them

But all to help keep the tank clean I guess. I do wonder if you could possibly get a larger ecosystem to help offset the need for water changes.