What y'all have to realize is I was around when this reef keeping hobby was in its infancy, made a LOT of mistakes, learned a lot along the way. If your tank isn't stable in 6 months, you need to look at why. I've done Dutch style systems with GOBs of caulerpa, plenums and now the Berlin systems. I've brought ritteris back that I got for free that looked like bloody hell and lost ones that were pristine condition, quarantined and treated with abx. What works for one persons system may or may not work for anothers. If there's a sudden change in a tank, it's because of something added 9 times out of 10, intentionally or not. I had a friend with a 180 system and we wracked our brains trying to figure out what was killing his inverts, corals and otherwise. One day we decided to pull all of the rock out of the tank and look at it because we were at a loss as to what the issue was. We got down to the bottom of the rock and I noticed a rock with a green stain on it, nah, couldn't be I thought. Sure enough it was a Japanese 7.7 round from WW2 trapped about 3cm inside the rock. We put everything back and his tank is beautiful 10 years later. I'm still of the opinion when you hear hoof beats think horses, not Zebras, but there's that one time......
BTAs are tough, mine have split themselves, been chopped to pieces by a wavemaker and chopped in 1/2 by the overflow and lived. My 130D is populated by these 3.