You know, I'm just all done with arguing with people. In everything. All we do as a species is argue, and if we all don't have the same opinions, someone gets upset, dogs and cats start living together, etc etc.
So I'm hesitant to argue. All I can say is that I run an ULN tank, BUT I have a DSB and pellets, so does that act as a nutrient buffer, perhaps, but I haven't had an unexplained crash or die-off since I switched from just letting nutrients do their own thing, to running a hard core GFO regimen, along with regular substrate vac sessions (along with carbon).
SO what I'm saying is that hey, maybe some people CAN run a tank with mid to high nutrients, and for sure, softies do better with higher nutrients, but sps can flourish with almost nothing in the water column (well besides trace elements etc). I just know that -for myself- I would never go back to the problems I had with high nutrients. In fact that last major pest I had was dinos, and that was a few years ago now, and it was at the tail end of a string of tank crashes and failures, I think I had 3 almost total crashes in ~20+ years of this, and 0 since I went to ULN. If I do water chages, the corals just take off (sps).
So I guess I didn't want to make a big deal out of this one, since I don't run a bare-bottom setup with absolute 0 nutrients or buffer, I have 4 inches of substrate, and it's not definitive. BUT I think (in my head), that nutrients cause way more problems in a closed biosphere like a fishtank, than trying for ULN and just doing regular or spot feeding of fish and/or coral. But even look at using old liverock in a new system. There's at least one thread on here right now about algae explosions off liverock during cycles. That's because the old liverock is chuck full of phosphates, and they're leeching into the water column, and algae has something to feed on. On this new build, I used old rock from my old ULN system (.34 Parts per billion Po4 when I shut down the old one), and some new rock I picked up, and the "new" rock looked like hairy bowling balls, while my old rock stayed white until coral started growing. To me, it's proof that a "clean" system is going to inherently have less problems than a dirty one.
what’s everyone’s thoughts on reusing aquarium sand ? Am I better off buying new sand ? 
