Darn, I quickly read through the 1st link and now I have more questions.
I have about 140 net gallons, have been running this:
~8 Tbsp of GFO changed every 4 weeks
~4-6 cups GAC
-3ml VSV (at GBD reccommended mix) TWICE daily (6ml total) stabil at this dose for 2 months
-Weekly 10% WC
~10 gal fuge with cheato harvested biweekly
SG 1.025, Mag 1450, CA 500, KH 9, PH ~8.1
All runs on a CA reactor, ATO with nielsen(kalk) ad MSX 300 skimmer rated at like 200 gallons at a heavy bioload (HUGE)
All parameters look good, According to elos N's and Ps undetectable. My par seems suitable, 500+ for most sps. YET, some still have not colored up, and still remain rusty or brownish. They perhaps hav lightened a little, but no real color improvement. Just light brown.
Some have improved a lot though, and some even look slightly pale (but not pastel).
I do not dose any supplements except for biodigest every 2 weeks.
I have vitamin C that I occasionally add to food, but maybe only one a week.
Any recommendations on adjustments or things to try? I have considered Potassium, but really dont think I need it with my water changes.
BTW, I dropped sugar this morning, gonna try 90/10 Vodka/Vinegar5%