So, I have been doing a lot of reading lately about amino acid dosing, based on a recommendation a few months ago by my LFS guy. What I have discovered is a bunch of inconclusive findings, but a million anecdotal accounts from people saying it makes a huge difference in an ULNS. I would say I am close to ULNS, but maybe not all the way there. My PO4 is consistently 0-0.03, and my NO3 consistently tests at 0 with a test kit that has resolution down to 0.25ppm Nitrate.
My LFS guy has an AMAZING zero edge 180 gallon SPS display tank in his store, and he swears the colors and growth of his SPS are due to ULNS and amino acid dosing. He uses either Aquavitro Fuel or Seachem Reef Plus (usually reef plus since he can get it in bulk), and swears by it. I decided to give it a try in my system and see if I notice in comparable difference in color and growth over the coming month. I can say that his tank is truly awe inspiring in terms of color and growth, so hopefully dosing amino acids will be the difference in my tank.
Anyone else using it or have any opinions on it? I'll post some more pics later as well... and perhaps setup some more side by side comparisons after a month of dosing according to directions on the bottle.