I have no problems with GARF whatsoever other than this. There is no such thing as a bulletproof reef. If there was, Aquarium Advice wouldn't even exist. Let's think about this.
You have 2 125g tanks. One contains a 3 foot long snowflake moray eel with only only mushrooms and zooanthids. The other tank contains a relatively small bioload but is stacked from top to bottom with SPS
corals, a couple clams, and maybe a few softies.
The calcium needs of the 2 tanks vary widely. The nitrate problems of the two tanks vary widely.
If you treated both of these tanks the same based on a "recipe" you are waiting for disaster. It's the "recipe" and word "bulletproof" that bother me.
Test, test, test. Do regular water changes with a quality water source and a quality salt. NEVER overfeed (it's tempting but there are more problems other than nitrates). Maintain your tank well. Read Aquarium Advice a lot. There are a lot of excellent articles and a lot of excellent posts.